SC16IS750 test and test on mux

Tested SC16IS750 (single channel UART) for compatibility
Tested on PCA9548 mux
Both successful

DCCEXParser.cpp

@@ -122,7 +122,7 @@ Once a new OPCODE is decided upon, update this list.
     for (int16_t i=0;;i+=sizeof(flashList[0])) {                            \
         int16_t value=GETHIGHFLASHW(flashList,i);       \
         if (value==INT16_MAX) break;                            \
-        if (value != 0) StringFormatter::send(stream,F(" %d"),value);	\
+        StringFormatter::send(stream,F(" %d"),value);	\
     }                                   
 
 
@@ -812,13 +812,12 @@ void DCCEXParser::parseOne(Print *stream, byte *com, RingStream * ringStream)
                         const FSH *tpdesc = NULL;
                         for (uint8_t p = 0; p < posCount; p++) {
                             StringFormatter::send(stream, F("<jP"));
-                            int16_t value = tto->getPositionValue(p);
                             int16_t angle = tto->getPositionAngle(p);
 #ifdef EXRAIL_ACTIVE
                             tpdesc = RMFT2::getTurntablePositionDescription(id, p);
 #endif
                             if (tpdesc == NULL) tpdesc = F("");
-                            StringFormatter::send(stream, F(" %d %d %d %d \"%S\""), id, p, value, angle, tpdesc);
+                            StringFormatter::send(stream, F(" %d %d %d \"%S\""), id, p, angle, tpdesc);
                             StringFormatter::send(stream, F(">\n"));
                         }
                     }
@@ -1058,7 +1057,7 @@ bool DCCEXParser::parseD(Print *stream, int16_t params, int16_t p[])
 
     case HASH_KEYWORD_RAM: // <D RAM>
         StringFormatter::send(stream, F("Free memory=%d\n"), DCCTimer::getMinimumFreeMemory());
-        break;
+        return true;
 
 #ifndef DISABLE_PROG
     case HASH_KEYWORD_ACK: // <D ACK ON/OFF> <D ACK [LIMIT|MIN|MAX|RETRY] Value>

DCCTimer.h

@@ -125,8 +125,13 @@ private:
   // On platforms that scan, it is called from waveform ISR
   // only on a regular basis.
   static void scan();
+  #if defined (ARDUINO_ARCH_STM32)
+  // bit array of used pins (max 32)
+  static uint32_t usedpins;
+#else
   // bit array of used pins (max 16)
   static uint16_t usedpins;
+#endif
   static uint8_t highestPin;
   // cached analog values (malloc:ed to actual number of ADC channels)
   static int *analogvals;

DCCTimerSTM32.cpp

@@ -1,6 +1,6 @@
 /*
  *  © 2023 Neil McKechnie
- *  © 2022-23 Paul M. Antoine
+ *  © 2022-2023 Paul M. Antoine
  *  © 2021 Mike S
  *  © 2021, 2023 Harald Barth
  *  © 2021 Fred Decker
@@ -52,7 +52,7 @@ HardwareSerial Serial6(PA12, PA11);  // Rx=PA12, Tx=PA11 -- CN10 pins 12 and 14
 HardwareSerial Serial3(PC11, PC10);  // Rx=PC11, Tx=PC10 -- USART3 - F446RE
 HardwareSerial Serial5(PD2, PC12);  // Rx=PC7, Tx=PC6 -- UART5 - F446RE
 // On the F446RE, Serial4 and Serial6 also use pins we can't readily map while using the Arduino pins
-#elif defined(ARDUINO_NUCLEO_F413ZH) || defined(ARDUINO_NUCLEO_F429ZI) || defined(ARDUINO_NUCLEO_F446ZE)|| defined(ARDUINO_NUCLEO_F412ZG) 
+#elif defined(ARDUINO_NUCLEO_F412ZG) || defined(ARDUINO_NUCLEO_F413ZH) || defined(ARDUINO_NUCLEO_F429ZI) || defined(ARDUINO_NUCLEO_F446ZE) 
 // Nucleo-144 boards don't have Serial1 defined by default
 HardwareSerial Serial6(PG9, PG14);  // Rx=PG9, Tx=PG14 -- USART6
 // Serial3 is defined to use USART3 by default, but is in fact used as the diag console
@@ -154,13 +154,28 @@ HardwareSerial Serial6(PG9, PG14);  // Rx=PG9, Tx=PG14 -- USART6
 ///////////////////////////////////////////////////////////////////////////////////////////////
 
 INTERRUPT_CALLBACK interruptHandler=0;
-// Let's use STM32's timer #11 until disabused of this notion
-// Timer #11 is used for "servo" library, but as DCC-EX is not using
-// this libary, we should be free and clear.
-HardwareTimer timer(TIM11);
+
+// On STM32F4xx models that have them, Timers 6 and 7 have no PWM output capability,
+// so are good choices for general timer duties - they are used for tone and servo
+// in stm32duino so we shall usurp those as DCC-EX doesn't use tone or servo libs.
+// NB: the F401, F410 and F411 do **not** have Timer 6 or 7, so we use Timer 11
+#ifndef DCC_EX_TIMER
+#if defined(TIM6)
+#define DCC_EX_TIMER TIM6
+#elif defined(TIM7)
+#define DCC_EX_TIMER TIM7
+#elif defined(TIM11)
+#define DCC_EX_TIMER TIM11
+#else
+#warning This STM32F4XX variant does not have Timers 6,7 or 11!!
+#endif
+#endif // ifndef DCC_EX_TIMER
+
+HardwareTimer dcctimer(DCC_EX_TIMER);
+void DCCTimer_Handler() __attribute__((interrupt));
 
 // Timer IRQ handler
-void Timer11_Handler() {
+void DCCTimer_Handler() {
   interruptHandler();
 }
 
@@ -168,22 +183,24 @@ void DCCTimer::begin(INTERRUPT_CALLBACK callback) {
   interruptHandler=callback;
   noInterrupts();
 
-  // adc_set_sample_rate(ADC_SAMPLETIME_480CYCLES);
-  timer.pause();
-  timer.setPrescaleFactor(1);
+  dcctimer.pause();
+  dcctimer.setPrescaleFactor(1);
 //  timer.setOverflow(CLOCK_CYCLES * 2);
-  timer.setOverflow(DCC_SIGNAL_TIME, MICROSEC_FORMAT);
-  timer.attachInterrupt(Timer11_Handler);
-  timer.refresh();
-  timer.resume();
+  dcctimer.setOverflow(DCC_SIGNAL_TIME, MICROSEC_FORMAT);
+  // dcctimer.attachInterrupt(Timer11_Handler);
+  dcctimer.attachInterrupt(DCCTimer_Handler);
+  dcctimer.setInterruptPriority(0, 0); // Set highest preemptive priority!
+  dcctimer.refresh();
+  dcctimer.resume();
 
   interrupts();
 }
 
 bool DCCTimer::isPWMPin(byte pin) {
-  //TODO: SAMD whilst this call to digitalPinHasPWM will reveal which pins can do PWM,
+  //TODO: STM32 whilst this call to digitalPinHasPWM will reveal which pins can do PWM,
   //      there's no support yet for High Accuracy, so for now return false
   //  return digitalPinHasPWM(pin);
+  (void) pin;
   return false;
 }
 
@@ -235,22 +252,91 @@ void DCCTimer::reset() {
     while(true) {};
 }
 
-// TODO: may need to use uint32_t on STMF4xx variants with > 16 analog inputs!
-#if defined(ARDUINO_NUCLEO_F446RE) || defined(ARDUINO_NUCLEO_F429ZI) || defined(ARDUINO_NUCLEO_F446ZE)
-#warning STM32 board selected not fully supported - only use ADC1 inputs 0-15 for current sensing!
-#endif
-// For now, define the max of 16 ports - some variants have more, but this not **yet** supported
-#define NUM_ADC_INPUTS 16
-// #define NUM_ADC_INPUTS NUM_ANALOG_INPUTS
+// TODO: rationalise the size of these... could really use sparse arrays etc.
+static HardwareTimer * pin_timer[100] = {0};
+static uint32_t channel_frequency[100] = {0};
+static uint32_t pin_channel[100] = {0};
 
-uint16_t ADCee::usedpins = 0;
-uint8_t ADCee::highestPin = 0;
-int * ADCee::analogvals = NULL;
-uint32_t * analogchans = NULL;
-bool adc1configured = false;
+// Using the HardwareTimer library API included in stm32duino core to handle PWM duties
+// TODO: in order to use the HA code above which Neil kindly wrote, we may have to do something more
+// sophisticated about detecting any clash between the timer we'd like to use for PWM and the ones
+// currently used for HA so they don't interfere with one another. For now we'll just make PWM
+// work well... then work backwards to integrate with HA mode if we can.
+void DCCTimer::DCCEXanalogWriteFrequency(uint8_t pin, uint32_t frequency)
+{
+  if (pin_timer[pin] == NULL) {
+    // Automatically retrieve TIM instance and channel associated to pin
+    // This is used to be compatible with all STM32 series automatically.
+    TIM_TypeDef *Instance = (TIM_TypeDef *)pinmap_peripheral(digitalPinToPinName(pin), PinMap_PWM);
+    if (Instance == NULL) {
+      // We shouldn't get here (famous last words) as it ought to have been caught by brakeCanPWM()!
+      DIAG(F("DCCEXanalogWriteFrequency::Pin %d has no PWM function!"), pin);
+      return;
+    }
+    pin_channel[pin] = STM_PIN_CHANNEL(pinmap_function(digitalPinToPinName(pin), PinMap_PWM));
 
-int16_t ADCee::ADCmax() {
-  return 4095;
+    // Instantiate HardwareTimer object. Thanks to 'new' instantiation,
+    // HardwareTimer is not destructed when setup function is finished.
+    pin_timer[pin] = new HardwareTimer(Instance);
+    // Configure and start PWM
+    // MyTim->setPWM(channel, pin, 5, 10, NULL, NULL); // No callback required, we can simplify the function call
+    if (pin_timer[pin] != NULL)
+    {
+      pin_timer[pin]->setPWM(pin_channel[pin], pin, frequency, 0); // set frequency in Hertz, 0% dutycycle
+      DIAG(F("DCCEXanalogWriteFrequency::Pin %d on Timer %d, frequency %d"), pin, pin_channel[pin], frequency);
+    }
+    else
+      DIAG(F("DCCEXanalogWriteFrequency::failed to allocate HardwareTimer instance!"));
+  }
+  else
+  {
+    // Frequency change request
+    if (frequency != channel_frequency[pin])
+    {
+      pinmap_pinout(digitalPinToPinName(pin), PinMap_TIM); // ensure the pin has been configured!
+      pin_timer[pin]->setOverflow(frequency, HERTZ_FORMAT); // Just change the frequency if it's already running!
+      DIAG(F("DCCEXanalogWriteFrequency::setting frequency to %d"), frequency);
+    }
+  }
+  channel_frequency[pin] = frequency;
+  return;
+}
+
+void DCCTimer::DCCEXanalogWrite(uint8_t pin, int value) {
+    // Calculate percentage duty cycle from value given
+    uint32_t duty_cycle = (value * 100 / 256) + 1;
+    if (pin_timer[pin] != NULL) {
+      // if (duty_cycle == 100)
+      // {
+      //   pin_timer[pin]->pauseChannel(pin_channel[pin]);
+      //   DIAG(F("DCCEXanalogWrite::Pausing timer channel on pin %d"), pin);
+      // }
+      // else
+      // {
+        pinmap_pinout(digitalPinToPinName(pin), PinMap_TIM); // ensure the pin has been configured!
+        // pin_timer[pin]->resumeChannel(pin_channel[pin]);
+        pin_timer[pin]->setCaptureCompare(pin_channel[pin], duty_cycle, PERCENT_COMPARE_FORMAT); // DCC_EX_PWM_FREQ Hertz, duty_cycle% dutycycle
+        DIAG(F("DCCEXanalogWrite::Pin %d, value %d, duty cycle %d"), pin, value, duty_cycle);
+      // }
+    }
+    else
+      DIAG(F("DCCEXanalogWrite::Pin %d is not configured for PWM!"), pin);
+}
+
+
+// Now we can handle more ADCs, maybe this works!
+#define NUM_ADC_INPUTS NUM_ANALOG_INPUTS
+
+uint32_t ADCee::usedpins = 0;         // Max of 32 ADC input channels!
+uint8_t ADCee::highestPin = 0;        // Highest pin to scan
+int * ADCee::analogvals = NULL;       // Array of analog values last captured
+uint32_t * analogchans = NULL;        // Array of channel numbers to be scanned
+// bool adc1configured = false;
+ADC_TypeDef * * adcchans = NULL;      // Array to capture which ADC is each input channel on
+
+int16_t ADCee::ADCmax()
+{
+    return 4095;
 }
 
 int ADCee::init(uint8_t pin) {
@@ -261,11 +347,33 @@ int ADCee::init(uint8_t pin) {
     return -1024;   // some silly value as error
 
   uint32_t stmgpio = STM_PORT(stmpin); // converts to the GPIO port (16-bits per port group on STM32)
-  uint32_t adcchan =  STM_PIN_CHANNEL(pinmap_function(stmpin, PinMap_ADC)); // find ADC channel (only valid for ADC1!)
-  GPIO_TypeDef * gpioBase;
+  uint32_t adcchan =  STM_PIN_CHANNEL(pinmap_function(stmpin, PinMap_ADC)); // find ADC input channel
+  ADC_TypeDef *adc = (ADC_TypeDef *)pinmap_find_peripheral(stmpin, PinMap_ADC); // find which ADC this pin is on ADC1/2/3 etc.
+  int adcnum = 1;
+  if (adc == ADC1)
+    DIAG(F("ADCee::init(): found pin %d on ADC1"), pin);
+// Checking for ADC2 and ADC3 being defined helps cater for more variants later
+#if defined(ADC2)
+  else if (adc == ADC2)
+  {
+    DIAG(F("ADCee::init(): found pin %d on ADC2"), pin);
+    adcnum = 2;
+  }
+#endif
+#if defined(ADC3)
+  else if (adc == ADC3)
+  {
+    DIAG(F("ADCee::init(): found pin %d on ADC3"), pin);
+    adcnum = 3;
+  }
+#endif
+  else DIAG(F("ADCee::init(): found pin %d on unknown ADC!"), pin);
 
-  // Port config - find which port we're on and power it up
-  switch(stmgpio) {
+    // Port config - find which port we're on and power it up
+    GPIO_TypeDef *gpioBase;
+
+    switch (stmgpio)
+    {
     case 0x00:
         RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN; //Power up PORTA
         gpioBase = GPIOA;
@@ -278,6 +386,20 @@ int ADCee::init(uint8_t pin) {
         RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; //Power up PORTC
         gpioBase = GPIOC;
         break;
+    case 0x03:
+        RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN; //Power up PORTD
+        gpioBase = GPIOD;
+        break;
+    case 0x04:
+        RCC->AHB1ENR |= RCC_AHB1ENR_GPIOEEN; //Power up PORTE
+        gpioBase = GPIOE;
+        break;
+#if defined(GPIOF)
+    case 0x05:
+        RCC->AHB1ENR |= RCC_AHB1ENR_GPIOFEN; //Power up PORTF
+        gpioBase = GPIOF;
+        break;
+#endif
     default:
       return -1023; // some silly value as error
   }
@@ -293,31 +415,33 @@ int ADCee::init(uint8_t pin) {
   if (adcchan > 18)
     return -1022; // silly value as error
   if (adcchan < 10)
-    ADC1->SMPR2 |= (0b111 << (adcchan * 3)); // Channel sampling rate 480 cycles
+    adc->SMPR2 |= (0b111 << (adcchan * 3)); // Channel sampling rate 480 cycles
   else
-    ADC1->SMPR1 |= (0b111 << ((adcchan - 10) * 3)); // Channel sampling rate 480 cycles
+    adc->SMPR1 |= (0b111 << ((adcchan - 10) * 3)); // Channel sampling rate 480 cycles
 
   // Read the inital ADC value for this analog input
-  ADC1->SQR3 = adcchan;           // 1st conversion in regular sequence
-  ADC1->CR2 |= (1 << 30);         // Start 1st conversion SWSTART
-  while(!(ADC1->SR & (1 << 1)));  // Wait until conversion is complete
-  value = ADC1->DR;               // Read value from register
+  adc->SQR3 = adcchan;           // 1st conversion in regular sequence
+  adc->CR2 |= ADC_CR2_SWSTART;   //(1 << 30);                     // Start 1st conversion SWSTART
+  while(!(adc->SR & (1 << 1)));  // Wait until conversion is complete
+  value = adc->DR;               // Read value from register
 
   uint8_t id = pin - PNUM_ANALOG_BASE;
-  if (id > 15) { // today we have not enough bits in the mask to support more
-    return -1021;
-  }
+  // if (id > 15) { // today we have not enough bits in the mask to support more
+  //   return -1021;
+  // }
 
-  if (analogvals == NULL) {  // allocate analogvals and analogchans if this is the first invocation of init.
+  if (analogvals == NULL) {  // allocate analogvals, analogchans and adcchans if this is the first invocation of init
     analogvals = (int *)calloc(NUM_ADC_INPUTS+1, sizeof(int));
     analogchans = (uint32_t *)calloc(NUM_ADC_INPUTS+1, sizeof(uint32_t));
+    adcchans = (ADC_TypeDef **)calloc(NUM_ADC_INPUTS+1, sizeof(ADC_TypeDef));
   }
   analogvals[id] = value;     // Store sampled value
   analogchans[id] = adcchan;  // Keep track of which ADC channel is used for reading this pin
-  usedpins |= (1 << id);      // This pin is now ready
+  adcchans[id] = adc;         // Keep track of which ADC this channel is on
+  usedpins |= (1 << id);                // This pin is now ready
   if (id > highestPin) highestPin = id; // Store our highest pin in use
 
-  DIAG(F("ADCee::init(): value=%d, channel=%d, id=%d"), value, adcchan, id);
+  DIAG(F("ADCee::init(): value=%d, ADC%d: channel=%d, id=%d"), value, adcnum, adcchan, id);
 
   return value;
 }
@@ -344,13 +468,16 @@ void ADCee::scan() {
   static uint8_t id = 0;     // id and mask are the same thing but it is faster to
   static uint16_t mask = 1;  // increment and shift instead to calculate mask from id
   static bool waiting = false;
+  static ADC_TypeDef *adc;
 
-  if (waiting) {
+  adc = adcchans[id];
+  if (waiting)
+  {
     // look if we have a result
-    if (!(ADC1->SR & (1 << 1)))
+    if (!(adc->SR & (1 << 1)))
       return; // no result, continue to wait
     // found value
-    analogvals[id] = ADC1->DR;
+    analogvals[id] = adc->DR;
     // advance at least one track
 #ifdef DEBUG_ADC
     if (id == 1) TrackManager::track[1]->setBrake(0);
@@ -369,9 +496,10 @@ void ADCee::scan() {
     // look for a valid track to sample or until we are around
     while (true) {
       if (mask  & usedpins) {
-	// start new ADC aquire on id
-        ADC1->SQR3 = analogchans[id]; //1st conversion in regular sequence
-        ADC1->CR2 |= (1 << 30); //Start 1st conversion SWSTART
+        // start new ADC aquire on id
+        adc = adcchans[id];
+        adc->SQR3 = analogchans[id]; // 1st conversion in regular sequence
+        adc->CR2 |= (1 << 30);       // Start 1st conversion SWSTART
 #ifdef DEBUG_ADC
 	if (id == 1) TrackManager::track[1]->setBrake(1);
 #endif
@@ -392,19 +520,83 @@ void ADCee::scan() {
 void ADCee::begin() {
   noInterrupts();
   //ADC1 config sequence
-  // TODO: currently defaults to ADC1, may need more to handle other members of STM32F4xx family
-  RCC->APB2ENR |= (1 << 8); //Enable ADC1 clock (Bit8) 
+  RCC->APB2ENR |= RCC_APB2ENR_ADC1EN; // Enable ADC1 clock
   // Set ADC prescaler - DIV8 ~ 40ms, DIV6 ~ 30ms, DIV4 ~ 20ms, DIV2 ~ 11ms
   ADC->CCR = (0 << 16); // Set prescaler 0=DIV2, 1=DIV4, 2=DIV6, 3=DIV8
   ADC1->CR1 &= ~(1 << 8); //SCAN mode disabled (Bit8)
   ADC1->CR1 &= ~(3 << 24); //12bit resolution (Bit24,25 0b00)
   ADC1->SQR1 = (1 << 20); //Set number of conversions projected (L[3:0] 0b0001) -> 1 conversion
+  // Disable the DMA controller for ADC1
+  ADC1->CR2 &= ~ADC_CR2_DMA;
   ADC1->CR2 &= ~(1 << 1); //Single conversion
   ADC1->CR2 &= ~(1 << 11); //Right alignment of data bits bit12....bit0
   ADC1->SQR1 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
   ADC1->SQR2 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
   ADC1->SQR3 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
   ADC1->CR2 |= (1 << 0); // Switch on ADC1
+  // Wait for ADC1 to become ready (calibration complete)
+  while (!(ADC1->CR2 & ADC_CR2_ADON)) {
+  }
+#if defined(ADC2)
+  // Enable the ADC2 clock
+  RCC->APB2ENR |= RCC_APB2ENR_ADC2EN;
+
+  // Initialize ADC2
+  ADC2->CR1 = 0; // Disable all channels
+  ADC2->CR2 = 0; // Clear CR2 register
+
+  ADC2->CR1 &= ~(1 << 8); //SCAN mode disabled (Bit8)
+  ADC2->CR1 &= ~(3 << 24); //12bit resolution (Bit24,25 0b00)
+  ADC2->SQR1 = (1 << 20); //Set number of conversions projected (L[3:0] 0b0001) -> 1 conversion
+  ADC2->CR2 &= ~ADC_CR2_DMA;   // Disable the DMA controller for ADC3
+  ADC2->CR2 &= ~(1 << 1); //Single conversion
+  ADC2->CR2 &= ~(1 << 11); //Right alignment of data bits bit12....bit0
+  ADC2->SQR1 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+  ADC2->SQR2 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+  ADC2->SQR3 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+
+  // Enable the ADC
+  ADC2->CR2 |= ADC_CR2_ADON;
+
+  // Wait for ADC2 to become ready (calibration complete)
+  while (!(ADC2->CR2 & ADC_CR2_ADON)) {
+  }
+
+  // Perform ADC3 calibration (optional)
+  // ADC3->CR2 |= ADC_CR2_CAL;
+  // while (ADC3->CR2 & ADC_CR2_CAL) {
+  // }
+#endif
+#if defined(ADC3)
+  // Enable the ADC3 clock
+  RCC->APB2ENR |= RCC_APB2ENR_ADC3EN;
+
+  // Initialize ADC3
+  ADC3->CR1 = 0; // Disable all channels
+  ADC3->CR2 = 0; // Clear CR2 register
+
+  ADC3->CR1 &= ~(1 << 8); //SCAN mode disabled (Bit8)
+  ADC3->CR1 &= ~(3 << 24); //12bit resolution (Bit24,25 0b00)
+  ADC3->SQR1 = (1 << 20); //Set number of conversions projected (L[3:0] 0b0001) -> 1 conversion
+  ADC3->CR2 &= ~ADC_CR2_DMA;   // Disable the DMA controller for ADC3
+  ADC3->CR2 &= ~(1 << 1); //Single conversion
+  ADC3->CR2 &= ~(1 << 11); //Right alignment of data bits bit12....bit0
+  ADC3->SQR1 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+  ADC3->SQR2 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+  ADC3->SQR3 &= ~(0x3FFFFFFF); //Clear whole 1st 30bits in register
+
+  // Enable the ADC
+  ADC3->CR2 |= ADC_CR2_ADON;
+
+  // Wait for ADC3 to become ready (calibration complete)
+  while (!(ADC3->CR2 & ADC_CR2_ADON)) {
+  }
+
+  // Perform ADC3 calibration (optional)
+  // ADC3->CR2 |= ADC_CR2_CAL;
+  // while (ADC3->CR2 & ADC_CR2_CAL) {
+  // }
+#endif
   interrupts();
 }
 #endif

EXRAIL2.h

@@ -26,6 +26,7 @@
 #include "IODevice.h"
 #include "Turnouts.h"
 #include "Turntables.h"
+#include "IO_I2CDFPLayer.h"
    
 // The following are the operation codes (or instructions) for a kind of virtual machine.
 // Each instruction is normally 3 bytes long with an operation code followed by a parameter.

GITHUB_SHA.h

@@ -1 +1 @@
-#define GITHUB_SHA "devel-202308302157Z"
+#define GITHUB_SHA "devel-202309241855Z"

I2CManager.cpp

@@ -54,6 +54,8 @@ static const FSH * guessI2CDeviceType(uint8_t address) {
     return F("Time-of-flight sensor");
   else if (address >= 0x3c && address <= 0x3d)
     return F("OLED Display");
+  else if (address >= 0x48 && address <= 0x57) // Henkk: Added SC16IS752 UART detection
+    return F("SC16IS752 UART");
   else if (address >= 0x48 && address <= 0x4f)
     return F("Analogue Inputs or PWM");
   else if (address >= 0x40 && address <= 0x4f)
@@ -64,6 +66,7 @@ static const FSH * guessI2CDeviceType(uint8_t address) {
     return F("Real-time clock"); 
   else if (address >= 0x70 && address <= 0x77)
     return F("I2C Mux");
+  else if (address >= 0x90 && address <= 0xAE);  
   else
     return F("?");
 }
@@ -92,7 +95,7 @@ void I2CManagerClass::begin(void) {
     // Probe and list devices.  Use standard mode 
     //  (clock speed 100kHz) for best device compatibility.
     _setClock(100000);
-    unsigned long originalTimeout = _timeout;
+    uint32_t originalTimeout = _timeout;
     setTimeout(1000);       // use 1ms timeout for probes
 
   #if defined(I2C_EXTENDED_ADDRESS)
@@ -363,4 +366,4 @@ void I2CAddress::toHex(const uint8_t value, char *buffer) {
 
 /* static */ bool I2CAddress::_addressWarningDone = false;
 
-#endif
+#endif

I2CManager.h

@@ -485,7 +485,7 @@ private:
   // When retries are enabled, the timeout applies to each
   // try, and failure from timeout does not get retried.
   // A value of 0 means disable timeout monitoring.
-  unsigned long _timeout = 100000UL;
+  uint32_t _timeout = 100000UL;
     
   // Finish off request block by waiting for completion and posting status.
   uint8_t finishRB(I2CRB *rb, uint8_t status);
@@ -532,14 +532,15 @@ private:
     uint8_t bytesToSend = 0;
     uint8_t bytesToReceive = 0;
     uint8_t operation = 0;
-    unsigned long startTime = 0;
+    uint32_t startTime = 0;
     uint8_t muxPhase = 0;
     uint8_t muxAddress = 0;
     uint8_t muxData[1];
     uint8_t deviceAddress;
     const uint8_t *sendBuffer;
     uint8_t *receiveBuffer;
-
+    uint8_t transactionState = 0;
+  
     volatile uint32_t pendingClockSpeed = 0;
 
     void startTransaction();

I2CManager_NonBlocking.h

@@ -172,6 +172,10 @@ void I2CManagerClass::startTransaction() {
  *  Function to queue a request block and initiate operations.
  ***************************************************************************/
 void I2CManagerClass::queueRequest(I2CRB *req) {
+
+  if (((req->operation & OPERATION_MASK) == OPERATION_READ) && req->readLen == 0)
+    return;  // Ignore null read
+
   req->status = I2C_STATUS_PENDING;
   req->nextRequest = NULL;
   ATOMIC_BLOCK() {
@@ -184,6 +188,7 @@ void I2CManagerClass::queueRequest(I2CRB *req) {
 
 }
 
+
 /***************************************************************************
  *  Initiate a write to an I2C device (non-blocking operation)
  ***************************************************************************/
@@ -240,8 +245,8 @@ void I2CManagerClass::checkForTimeout() {
     I2CRB *t = queueHead;
     if (state==I2C_STATE_ACTIVE && t!=0 && t==currentRequest && _timeout > 0) {
       // Check for timeout
-      unsigned long elapsed = micros() - startTime;
-      if (elapsed > _timeout) { 
+      int32_t elapsed = micros() - startTime;
+      if (elapsed > (int32_t)_timeout) { 
 #ifdef DIAG_IO
         //DIAG(F("I2CManager Timeout on %s"), t->i2cAddress.toString());
 #endif
@@ -300,12 +305,12 @@ void I2CManagerClass::handleInterrupt() {
 
   // Check if current request has completed.  If there's a current request
   // and state isn't active then state contains the completion status of the request.
-  if (state == I2C_STATE_COMPLETED && currentRequest != NULL) {
+  if (state == I2C_STATE_COMPLETED && currentRequest != NULL && currentRequest == queueHead) {
     // Operation has completed.
     if (completionStatus == I2C_STATUS_OK || ++retryCounter > MAX_I2C_RETRIES
       || currentRequest->operation & OPERATION_NORETRY) 
     {
-      // Status is OK, or has failed and retry count exceeded, or retries disabled.
+      // Status is OK, or has failed and retry count exceeded, or failed and retries disabled.
 #if defined(I2C_EXTENDED_ADDRESS)
       if (muxPhase == MuxPhase_PROLOG ) {
         overallStatus = completionStatus;

I2CManager_STM32.h

@@ -26,27 +26,44 @@
 #include "I2CManager.h"
 #include "I2CManager_NonBlocking.h"   // to satisfy intellisense
 
-//#include <avr/io.h>
-//#include <avr/interrupt.h>
 #include <wiring_private.h>
+#include "stm32f4xx_hal_rcc.h"
 
-/***************************************************************************
- *  Interrupt handler.
- *  IRQ handler for SERCOM3 which is the default I2C definition for Arduino Zero
- *  compatible variants such as the Sparkfun SAMD21 Dev Breakout etc.
- *  Later we may wish to allow use of an alternate I2C bus, or more than one I2C
- *  bus on the SAMD architecture 
- ***************************************************************************/
+/*****************************************************************************
+ *  STM32F4xx I2C native driver support
+ * 
+ *  Nucleo-64 and Nucleo-144 boards all use I2C1 as the default I2C peripheral
+ *  Later we may wish to support other STM32 boards, allow use of an alternate
+ *  I2C bus, or more than one I2C bus on the STM32 architecture 
+ *****************************************************************************/
 #if defined(I2C_USE_INTERRUPTS) && defined(ARDUINO_ARCH_STM32)
-void I2C1_IRQHandler() {
+#if defined(ARDUINO_NUCLEO_F401RE) || defined(ARDUINO_NUCLEO_F411RE) || defined(ARDUINO_NUCLEO_F446RE) \
+    || defined(ARDUINO_NUCLEO_F412ZG) || defined(ARDUINO_NUCLEO_F413ZH) \
+    || defined(ARDUINO_NUCLEO_F429ZI) || defined(ARDUINO_NUCLEO_F446ZE)
+// Assume I2C1 for now - default I2C bus on Nucleo-F411RE and likely all Nucleo-64
+// and Nucleo-144 variants
+I2C_TypeDef *s = I2C1;
+
+// In init we will ask the STM32 HAL layer for the configured APB1 clock frequency in Hz
+uint32_t APB1clk1; // Peripheral Input Clock speed in Hz.
+uint32_t i2c_MHz;  // Peripheral Input Clock speed in MHz.
+
+// IRQ handler for I2C1, replacing the weak definition in the STM32 HAL 
+extern "C" void I2C1_EV_IRQHandler(void) {
   I2CManager.handleInterrupt();
 }
+extern "C" void I2C1_ER_IRQHandler(void) {
+  I2CManager.handleInterrupt();
+}
+#else
+#warning STM32 board selected is not yet supported - so I2C1 peripheral is not defined
+#endif
 #endif
 
-// Assume I2C1 for now - default I2C bus on Nucleo-F411RE and likely Nucleo-64 variants
-I2C_TypeDef *s = I2C1;
-#define I2C_IRQn  I2C1_EV_IRQn
-#define I2C_BUSFREQ 16
+// Peripheral Input Clock speed in MHz.
+// For STM32F446RE, the speed is 45MHz.  Ideally, this should be determined
+// at run-time from the APB1 clock, as it can vary from STM32 family to family.
+// #define I2C_PERIPH_CLK 45
 
 // I2C SR1 Status Register #1 bit definitions for convenience
 // #define I2C_SR1_SMBALERT  (1<<15)   // SMBus alert
@@ -80,52 +97,66 @@ I2C_TypeDef *s = I2C1;
 // #define I2C_CR1_SMBUS     (1<<1)    // SMBus mode, 1=SMBus, 0=I2C
 // #define I2C_CR1_PE        (1<<0)    // I2C Peripheral enable
 
+// States of the STM32 I2C driver state machine
+enum {TS_IDLE,TS_START,TS_W_ADDR,TS_W_DATA,TS_W_STOP,TS_R_ADDR,TS_R_DATA,TS_R_STOP};
+
+
 /***************************************************************************
  *  Set I2C clock speed register.  This should only be called outside of
  *  a transmission.  The I2CManagerClass::_setClock() function ensures 
  *  that it is only called at the beginning of an I2C transaction.
  ***************************************************************************/
 void I2CManagerClass::I2C_setClock(uint32_t i2cClockSpeed) {
-
   // Calculate a rise time appropriate to the requested bus speed
-  // Use 10x the rise time spec to enable integer divide of 62.5ns clock period
+  // Use 10x the rise time spec to enable integer divide of 50ns clock period
   uint16_t t_rise;
   uint32_t ccr_freq;
-  if (i2cClockSpeed < 200000L) {
-    // i2cClockSpeed = 100000L;
-    t_rise = 0x11;  // (1000ns /62.5ns) + 1;
-  }
-  else if (i2cClockSpeed < 800000L)
+
+  while (s->CR1 & I2C_CR1_STOP);  // Prevents lockup by guarding further
+                                  // writes to CR1 while STOP is being executed!
+
+  // Disable the I2C device, as TRISE can only be programmed whilst disabled
+  s->CR1 &= ~(I2C_CR1_PE);  // Disable I2C
+  s->CR1 |= I2C_CR1_SWRST;  // reset the I2C
+  asm("nop");    // wait a bit... suggestion from online!
+  s->CR1 &= ~(I2C_CR1_SWRST); // Normal operation
+
+  if (i2cClockSpeed > 100000UL)
   {
-    i2cClockSpeed = 400000L;
-    t_rise = 0x06;  // (300ns / 62.5ns) + 1;
-    // } else if (i2cClockSpeed < 1200000L) {
-    //   i2cClockSpeed = 1000000L;
-    //   t_rise = 120;
+    // if (i2cClockSpeed > 400000L)
+    //   i2cClockSpeed = 400000L;
+
+    t_rise = 300;  // nanoseconds
   }
   else
   {
-    i2cClockSpeed = 100000L;
-    t_rise = 0x11;  // (1000ns /62.5ns) + 1;
+    // i2cClockSpeed = 100000L;
+    t_rise = 1000;  // nanoseconds
   }
-
-  // Enable the I2C master mode
-  s->CR1 &= ~(I2C_CR1_PE);  // Enable I2C
-  // Software reset the I2C peripheral
-  // s->CR1 |= I2C_CR1_SWRST;  // reset the I2C
-  // Release reset
-  // s->CR1 &= ~(I2C_CR1_SWRST);  // Normal operation
-
-  // Calculate baudrate - using a rise time appropriate for the speed
-  ccr_freq = I2C_BUSFREQ * 1000000 / i2cClockSpeed / 2;
+  // Configure the rise time register - max allowed tRISE is 1000ns,
+  // so value = 1000ns * I2C_PERIPH_CLK MHz / 1000 + 1.
+  s->TRISE = (t_rise * i2c_MHz / 1000) + 1;
 
   // Bit 15: I2C Master mode, 0=standard, 1=Fast Mode
-  // Bit 14: Duty, fast mode duty cycle
-  // Bit 11-0: FREQR = 16MHz => TPCLK1 = 62.5ns, so CCR divisor must be 0x50 (80 * 62.5ns = 5000ns)
-  s->CCR = (uint16_t)ccr_freq;
+  // Bit 14: Duty, fast mode duty cycle (use 2:1)
+  // Bit 11-0: FREQR
+  // if (i2cClockSpeed > 400000UL) {
+  //   // In fast mode plus, I2C period is 3 * CCR * TPCLK1.
+  //   // s->CCR &= ~(0x3000); // Clear all bits except 12 and 13 which must remain per reset value
+  //   s->CCR = APB1clk1 / 3 / i2cClockSpeed; // Set I2C clockspeed to start!
+  //   s->CCR |= 0xC000; // We need Fast Mode AND DUTY bits set
+  // } else {
+    // In standard and fast mode, I2C period is 2 * CCR * TPCLK1
+    s->CCR &= ~(0x3000); // Clear all bits except 12 and 13 which must remain per reset value
+    s->CCR |= (APB1clk1 / 2 / i2cClockSpeed); // Set I2C clockspeed to start!
+    // s->CCR |= (i2c_MHz * 500 / (i2cClockSpeed / 1000)); // Set I2C clockspeed to start!
+    // if (i2cClockSpeed > 100000UL)
+    //     s->CCR |= 0xC000; // We need Fast Mode bits set as well
+  // }
 
-  // Configure the rise time register
-  s->TRISE = t_rise;  // 1000 ns / 62.5 ns = 16 + 1
+  // DIAG(F("I2C_init() peripheral clock is now: %d, full reg is %x"), (s->CR2 & 0xFF), s->CR2);
+  // DIAG(F("I2C_init() peripheral CCR is now: %d"), s->CCR);
+  // DIAG(F("I2C_init() peripheral TRISE is now: %d"), s->TRISE);
 
   // Enable the I2C master mode
   s->CR1 |= I2C_CR1_PE;  // Enable I2C
@@ -136,32 +167,54 @@ void I2CManagerClass::I2C_setClock(uint32_t i2cClockSpeed) {
  ***************************************************************************/
 void I2CManagerClass::I2C_init()
 {
-  //Setting up the clocks
-  RCC->APB1ENR |= (1<<21);  // Enable I2C CLOCK
-  RCC->AHB1ENR |= (1<<1);   // Enable GPIOB CLOCK for PB8/PB9
+  // Query the clockspeed from the STM32 HAL layer
+  APB1clk1 = HAL_RCC_GetPCLK1Freq();
+  i2c_MHz = APB1clk1 / 1000000UL;
+  // DIAG(F("I2C_init() peripheral clock speed is: %d"), i2c_MHz);
+  // Enable clocks
+  RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;//(1 << 21); // Enable I2C CLOCK
+  // Reset the I2C1 peripheral to initial state
+  RCC->APB1RSTR |=  RCC_APB1RSTR_I2C1RST;
+	RCC->APB1RSTR &= ~RCC_APB1RSTR_I2C1RST;
   // Standard I2C pins are SCL on PB8 and SDA on PB9
+  RCC->AHB1ENR |= (1<<1);   // Enable GPIOB CLOCK for PB8/PB9
   // Bits (17:16)= 1:0 --> Alternate Function for Pin PB8;
   // Bits (19:18)= 1:0 --> Alternate Function for Pin PB9
+  GPIOB->MODER &= ~((3<<(8*2)) | (3<<(9*2)));    // Clear all MODER bits for PB8 and PB9
   GPIOB->MODER |= (2<<(8*2)) | (2<<(9*2));    // PB8 and PB9 set to ALT function
   GPIOB->OTYPER |= (1<<8) | (1<<9);           // PB8 and PB9 set to open drain output capability
   GPIOB->OSPEEDR |= (3<<(8*2)) | (3<<(9*2));  // PB8 and PB9 set to High Speed mode
+  GPIOB->PUPDR &= ~((3<<(8*2)) | (3<<(9*2))); // Clear all PUPDR bits for PB8 and PB9
   GPIOB->PUPDR |= (1<<(8*2)) | (1<<(9*2));    // PB8 and PB9 set to pull-up capability
   // Alt Function High register routing pins PB8 and PB9 for I2C1:
   // Bits (3:2:1:0) = 0:1:0:0 --> AF4 for pin PB8
   // Bits (7:6:5:4) = 0:1:0:0 --> AF4 for pin PB9
+  GPIOB->AFR[1] &= ~((15<<0) | (15<<4));      // Clear all AFR bits for PB8 on low nibble, PB9 on next nibble up
   GPIOB->AFR[1] |= (4<<0) | (4<<4);           // PB8 on low nibble, PB9 on next nibble up
 
   // Software reset the I2C peripheral
+  I2C1->CR1 &= ~I2C_CR1_PE; // Disable I2C1 peripheral
   s->CR1 |= I2C_CR1_SWRST;  // reset the I2C
-  s->CR1 &= ~(I2C_CR1_SWRST);  // Normal operation
+  asm("nop");    // wait a bit... suggestion from online!
+  s->CR1 &= ~(I2C_CR1_SWRST); // Normal operation
 
-  // Program the peripheral input clock in CR2 Register in order to generate correct timings
-  s->CR2 |= I2C_BUSFREQ;  // PCLK1 FREQUENCY in MHz
+  // Clear all bits in I2C CR2 register except reserved bits
+  s->CR2 &= 0xE000;
+
+  // Set I2C peripheral clock frequency
+  // s->CR2 |= I2C_PERIPH_CLK;
+  s->CR2 |= i2c_MHz;
+  // DIAG(F("I2C_init() peripheral clock is now: %d"), s->CR2);
+
+  // set own address to 00 - not used in master mode
+  I2C1->OAR1 = (1 << 14); // bit 14 should be kept at 1 according to the datasheet
 
 #if defined(I2C_USE_INTERRUPTS)
   // Setting NVIC
-  NVIC_SetPriority(I2C_IRQn, 1);  // Match default priorities
-  NVIC_EnableIRQ(I2C_IRQn);
+  NVIC_SetPriority(I2C1_EV_IRQn, 1);  // Match default priorities
+  NVIC_EnableIRQ(I2C1_EV_IRQn);
+  NVIC_SetPriority(I2C1_ER_IRQn, 1);  // Match default priorities
+  NVIC_EnableIRQ(I2C1_ER_IRQn);
 
   // CR2 Interrupt Settings
   // Bit 15-13: reserved
@@ -172,23 +225,28 @@ void I2CManagerClass::I2C_init()
   // Bit 8: ITERREN - Error interrupt enable
   // Bit 7-6: reserved
   // Bit 5-0: FREQ - Peripheral clock frequency (max 50MHz)
-  // s->CR2 |= 0x0700;   // Enable Buffer, Event and Error interrupts
-  s->CR2 |= 0x0300;   // Enable Event and Error interrupts
+  s->CR2 |= (I2C_CR2_ITBUFEN | I2C_CR2_ITEVTEN | I2C_CR2_ITERREN);   // Enable Buffer, Event and Error interrupts
 #endif
 
+  // DIAG(F("I2C_init() setting initial I2C clock to 100KHz"));
   // Calculate baudrate and set default rate for now
   // Configure the Clock Control Register for 100KHz SCL frequency
   // Bit 15: I2C Master mode, 0=standard, 1=Fast Mode
   // Bit 14: Duty, fast mode duty cycle
-  // Bit 11-0: FREQR = 16MHz => TPCLK1 = 62.5ns, so CCR divisor must be 0x50 (80 * 62.5ns = 5000ns)
-  s->CCR = 0x0050;
+  // Bit 11-0: so CCR divisor would be clk / 2 / 100000 (where clk is in Hz)
+  // s->CCR = I2C_PERIPH_CLK * 5;
+  s->CCR &= ~(0x3000); // Clear all bits except 12 and 13 which must remain per reset value
+  s->CCR |= (APB1clk1 / 2 / 100000UL); // Set a default of 100KHz I2C clockspeed to start!
 
-  // Configure the rise time register - max allowed in 1000ns
-  s->TRISE = 0x0011; // 1000 ns / 62.5 ns = 16 + 1
+  // Configure the rise time register - max allowed is 1000ns, so value = 1000ns * I2C_PERIPH_CLK MHz / 1000 + 1.
+  s->TRISE = (1000 * i2c_MHz / 1000) + 1;
+
+  // DIAG(F("I2C_init() peripheral clock is now: %d, full reg is %x"), (s->CR2 & 0xFF), s->CR2);
+  // DIAG(F("I2C_init() peripheral CCR is now: %d"), s->CCR);
+  // DIAG(F("I2C_init() peripheral TRISE is now: %d"), s->TRISE);
 
   // Enable the I2C master mode
   s->CR1 |= I2C_CR1_PE;  // Enable I2C
-  // Setting bus idle mode and wait for sync
 }
 
 /***************************************************************************
@@ -198,49 +256,30 @@ void I2CManagerClass::I2C_sendStart() {
 
   // Set counters here in case this is a retry.
   rxCount = txCount = 0;
-  uint8_t temp;
 
-  // On a single-master I2C bus, the start bit won't be sent until the bus 
-  // state goes to IDLE so we can request it without waiting.  On a 
-  // multi-master bus, the bus may be BUSY under control of another master, 
+  // On a single-master I2C bus, the start bit won't be sent until the bus
+  // state goes to IDLE so we can request it without waiting.  On a
+  // multi-master bus, the bus may be BUSY under control of another master,
   // in which case we can avoid some arbitration failures by waiting until
   // the bus state is IDLE.  We don't do that here.
+  //while (s->SR2 & I2C_SR2_BUSY) {}
 
-  // If anything to send, initiate write.  Otherwise initiate read.
-  if (operation == OPERATION_READ || ((operation == OPERATION_REQUEST) && !bytesToSend))
-  {
-    // Send start for read operation
-    s->CR1 |= I2C_CR1_ACK;  // Enable the ACK
-    s->CR1 |= I2C_CR1_START;  // Generate START
-    // Send address with read flag (1) or'd in
-    s->DR = (deviceAddress << 1) | 1;  //  send the address
-    while (!(s->SR1 && I2C_SR1_ADDR));  // wait for ADDR bit to set
-    // Special case for 1 byte reads!
-    if (bytesToReceive == 1)
-    {
-      s->CR1 &= ~I2C_CR1_ACK;            // clear the ACK bit 
-		  temp = I2C1->SR1 | I2C1->SR2;  // read SR1 and SR2 to clear the ADDR bit.... EV6 condition
-		  s->CR1 |= I2C_CR1_STOP;              // Stop I2C
-    }
-    else
-      temp = s->SR1 | s->SR2;        // read SR1 and SR2 to clear the ADDR bit
-  }
-  else {
-    // Send start for write operation
-    s->CR1 |= I2C_CR1_ACK;  // Enable the ACK
-    s->CR1 |= I2C_CR1_START;  // Generate START
-    // Send address with write flag (0) or'd in
-    s->DR = (deviceAddress << 1) | 0;  //  send the address
-    while (!(s->SR1 && I2C_SR1_ADDR));  // wait for ADDR bit to set
-    temp = s->SR1 | s->SR2;  // read SR1 and SR2 to clear the ADDR bit
-  }
+  // Check there's no STOP still in progress.  If we OR the START bit into CR1
+  // and the STOP bit is already set, we could output multiple STOP conditions.
+  while (s->CR1 & I2C_CR1_STOP) {}  // Wait for STOP bit to reset
+
+  s->CR2 |= (I2C_CR2_ITEVTEN | I2C_CR2_ITERREN);  // Enable interrupts
+  s->CR2 &= ~I2C_CR2_ITBUFEN;     // Don't enable buffer interupts yet.
+  s->CR1 &= ~I2C_CR1_POS;   // Clear the POS bit
+  s->CR1 |= (I2C_CR1_ACK | I2C_CR1_START);   // Enable the ACK and generate START
+  transactionState = TS_START;
 }
 
 /***************************************************************************
  *  Initiate a stop bit for transmission (does not interrupt)
  ***************************************************************************/
 void I2CManagerClass::I2C_sendStop() {
-  s->CR1 |= I2C_CR1_STOP;              // Stop I2C
+  s->CR1 |= I2C_CR1_STOP; // Stop I2C
 }
 
 /***************************************************************************
@@ -252,9 +291,11 @@ void I2CManagerClass::I2C_close() {
   s->CR1 &= ~I2C_CR1_PE;  // Disable I2C peripheral
   // Should never happen, but wait for up to 500us only.
   unsigned long startTime = micros();
-  while ((s->CR1 && I2C_CR1_PE) != 0) {
-    if (micros() - startTime >= 500UL) break;
+  while ((s->CR1 & I2C_CR1_PE) != 0) {
+    if ((int32_t)(micros() - startTime) >= 500) break;
   }
+  NVIC_DisableIRQ(I2C1_EV_IRQn);
+  NVIC_DisableIRQ(I2C1_ER_IRQn);
 }
 
 /***************************************************************************
@@ -263,50 +304,217 @@ void I2CManagerClass::I2C_close() {
  *  (and therefore, indirectly, from I2CRB::wait() and I2CRB::isBusy()).
  ***************************************************************************/
 void I2CManagerClass::I2C_handleInterrupt() {
+  volatile uint16_t temp_sr1, temp_sr2;
 
-  if (s->SR1 && I2C_SR1_ARLO) {
-    // Arbitration lost, restart
-    I2C_sendStart();   // Reinitiate request
-  } else if (s->SR1 && I2C_SR1_BERR) {
-    // Bus error
-    completionStatus = I2C_STATUS_BUS_ERROR;
-    state = I2C_STATE_COMPLETED;
-  } else if (s->SR1 && I2C_SR1_TXE) {
-    // Master write completed
-    if (s->SR1 && (1<<10)) {
-      // Nacked, send stop.
-      I2C_sendStop();
+  temp_sr1 = s->SR1;
+
+  // Check for errors first
+  if (temp_sr1 & (I2C_SR1_AF | I2C_SR1_ARLO | I2C_SR1_BERR)) {
+    // Check which error flag is set
+    if (temp_sr1 & I2C_SR1_AF)
+    {
+      s->SR1 &= ~(I2C_SR1_AF); // Clear AF
+      I2C_sendStop(); // Clear the bus
+      transactionState = TS_IDLE;
       completionStatus = I2C_STATUS_NEGATIVE_ACKNOWLEDGE;
       state = I2C_STATE_COMPLETED;
-    } else if (bytesToSend) {
-      // Acked, so send next byte
-      s->DR = sendBuffer[txCount++];
-      bytesToSend--;
-    } else if (bytesToReceive) {
-      // Last sent byte acked and no more to send.  Send repeated start, address and read bit.
-      // s->I2CM.ADDR.bit.ADDR = (deviceAddress << 1) | 1;
-    } else {
-      // Check both TxE/BTF == 1 before generating stop
-      while (!(s->SR1 && I2C_SR1_TXE));    // Check TxE
-      while (!(s->SR1 && I2C_SR1_BTF));    // Check BTF
-      // No more data to send/receive. Initiate a STOP condition and finish
-      I2C_sendStop();
+    }
+    else if (temp_sr1 & I2C_SR1_ARLO)
+    {
+      // Arbitration lost, restart
+      s->SR1 &= ~(I2C_SR1_ARLO); // Clear ARLO
+      I2C_sendStart(); // Reinitiate request
+      transactionState = TS_START;
+    }
+    else if (temp_sr1 & I2C_SR1_BERR)
+    {
+      // Bus error
+      s->SR1 &= ~(I2C_SR1_BERR); // Clear BERR
+      I2C_sendStop(); // Clear the bus
+      transactionState = TS_IDLE;
+      completionStatus = I2C_STATUS_BUS_ERROR;
       state = I2C_STATE_COMPLETED;
     }
-  } else if (s->SR1 && I2C_SR1_RXNE) {
-    // Master read completed without errors
-    if (bytesToReceive == 1) {
-//      s->I2CM.CTRLB.bit.ACKACT = 1;  // NAK final byte
-      I2C_sendStop();  // send stop
-      receiveBuffer[rxCount++] = s->DR;  // Store received byte
-      bytesToReceive = 0;
-      state = I2C_STATE_COMPLETED;
-    } else if (bytesToReceive) {
-//      s->I2CM.CTRLB.bit.ACKACT = 0;  // ACK all but final byte
-      receiveBuffer[rxCount++] = s->DR;  // Store received byte
-      bytesToReceive--;
+  } 
+  else {
+    // No error flags, so process event according to current state.
+    switch (transactionState) {
+      case TS_START:
+        if (temp_sr1 & I2C_SR1_SB) {
+          // Event EV5
+          // Start bit has been sent successfully and we have the bus.
+          // If anything to send, initiate write.  Otherwise initiate read.
+          if (operation == OPERATION_READ || ((operation == OPERATION_REQUEST) && !bytesToSend)) {
+            // Send address with read flag (1) or'd in
+            s->DR = (deviceAddress << 1) | 1;  //  send the address
+            transactionState = TS_R_ADDR;
+          } else {
+            // Send address with write flag (0) or'd in
+            s->DR = (deviceAddress << 1) | 0;  //  send the address
+            transactionState = TS_W_ADDR;
+          }
+        }
+        // SB bit is cleared by writing to DR (already done).
+        break;
+
+      case TS_W_ADDR:
+        if (temp_sr1 & I2C_SR1_ADDR) {
+          temp_sr2 = s->SR2; // read SR2 to complete clearing the ADDR bit
+          // Event EV6
+          // Address sent successfully, device has ack'd in response.
+          if (!bytesToSend) {
+            I2C_sendStop();
+            transactionState = TS_IDLE;
+            completionStatus = I2C_STATUS_OK;
+            state = I2C_STATE_COMPLETED;
+          } else {
+            // Put one byte into DR to load shift register.
+            s->DR = sendBuffer[txCount++];
+            bytesToSend--;
+            if (bytesToSend) {
+              // Put another byte to load DR
+              s->DR = sendBuffer[txCount++];
+              bytesToSend--;
+            }
+            if (!bytesToSend) {
+              // No more bytes to send.
+              // The TXE interrupt occurs when the DR is empty, and the BTF interrupt 
+              // occurs when the shift register is also empty (one character later).
+              // To avoid repeated TXE interrupts during this time, we disable TXE interrupt.
+              s->CR2 &= ~I2C_CR2_ITBUFEN;  // Wait for BTF interrupt, disable TXE interrupt
+              transactionState = TS_W_STOP;
+            } else {
+              // More data remaining to send after this interrupt, enable TXE interrupt.
+              s->CR2 |= I2C_CR2_ITBUFEN;
+              transactionState = TS_W_DATA;
+            }
+          }
+        }
+        break;
+
+      case TS_W_DATA:
+        if (temp_sr1 & I2C_SR1_TXE) {
+          // Event EV8_1/EV8
+          // Transmitter empty, write a byte to it.
+          if (bytesToSend) {
+            s->DR = sendBuffer[txCount++];
+            bytesToSend--;
+            if (!bytesToSend) {
+              s->CR2 &= ~I2C_CR2_ITBUFEN;  // Disable TXE interrupt
+              transactionState = TS_W_STOP;
+            }
+          }
+        } 
+        break;
+
+      case TS_W_STOP:
+        if (temp_sr1 & I2C_SR1_BTF) {
+          // Event EV8_2
+          // Done, last character sent. Anything to receive?
+          if (bytesToReceive) {
+            I2C_sendStart();
+            // NOTE: Three redundant BTF interrupts take place between the
+            // first BTF interrupt and the START interrupt.  I've tried all sorts
+            // of ways to eliminate them, and the only thing that worked for
+            // me was to loop until the BTF bit becomes reset.  Either way,
+            // it's a waste of processor time.  Anyone got a solution?
+            //while (s->SR1 && I2C_SR1_BTF) {}
+            transactionState = TS_START;
+          } else {
+            I2C_sendStop();
+            transactionState = TS_IDLE;
+            completionStatus = I2C_STATUS_OK;
+            state = I2C_STATE_COMPLETED;
+          }
+          s->SR1 &= I2C_SR1_BTF;  // Clear BTF interrupt
+        }
+        break;
+
+      case TS_R_ADDR:
+        if (temp_sr1 & I2C_SR1_ADDR) {
+          // Event EV6
+          // Address sent for receive.
+          // The next bit is different depending on whether there are 
+          // 1 byte, 2 bytes or >2 bytes to be received, in accordance with the
+          // Programmers Reference RM0390.
+          if (bytesToReceive == 1) {
+            // Receive 1 byte
+            s->CR1 &= ~I2C_CR1_ACK;  // Disable ack
+            temp_sr2 = s->SR2; // read SR2 to complete clearing the ADDR bit
+            // Next step will occur after a RXNE interrupt, so enable it
+            s->CR2 |= I2C_CR2_ITBUFEN;
+            transactionState = TS_R_STOP;
+          } else if (bytesToReceive == 2) {
+            // Receive 2 bytes
+            s->CR1 &= ~I2C_CR1_ACK;  // Disable ACK for final byte
+            s->CR1 |= I2C_CR1_POS;  // set POS flag to delay effect of ACK flag
+            // Next step will occur after a BTF interrupt, so disable RXNE interrupt
+            s->CR2 &= ~I2C_CR2_ITBUFEN;
+            temp_sr2 = s->SR2; // read SR2 to complete clearing the ADDR bit
+            transactionState = TS_R_STOP;
+          } else {
+            // >2 bytes, just wait for bytes to come in and ack them for the time being
+            // (ack flag has already been set).
+            // Next step will occur after a BTF interrupt, so disable RXNE interrupt
+            s->CR2 &= ~I2C_CR2_ITBUFEN;
+            temp_sr2 = s->SR2; // read SR2 to complete clearing the ADDR bit
+            transactionState = TS_R_DATA;
+          }
+        }
+        break;
+      
+      case TS_R_DATA:
+        // Event EV7/EV7_1
+        if (temp_sr1 & I2C_SR1_BTF) {
+          // Byte received in receiver - read next byte
+          if (bytesToReceive == 3) {
+            // Getting close to the last byte, so a specific sequence is recommended.
+            s->CR1 &= ~I2C_CR1_ACK;  // Reset ack for next byte received.
+            transactionState = TS_R_STOP;
+          }
+          receiveBuffer[rxCount++] = s->DR;  // Store received byte
+          bytesToReceive--;
+        } 
+        break;
+        
+      case TS_R_STOP:
+        if (temp_sr1 & I2C_SR1_BTF) {
+          // Event EV7 (last one)
+          // When we've got here, the receiver has got the last two bytes
+          // (or one byte, if only one byte is being received),
+          // and NAK has already been sent, so we need to read from the receiver.
+          if (bytesToReceive) {
+            if (bytesToReceive > 1) 
+              I2C_sendStop();
+            while(bytesToReceive) {
+              receiveBuffer[rxCount++] = s->DR;  // Store received byte(s)
+              bytesToReceive--;
+            }
+            // Finish.
+            transactionState = TS_IDLE;
+            completionStatus = I2C_STATUS_OK;
+            state = I2C_STATE_COMPLETED;
+          }
+        } else if (temp_sr1 & I2C_SR1_RXNE) {
+          if (bytesToReceive == 1) {
+            // One byte on a single-byte transfer.  Ack has already been set.
+            I2C_sendStop();
+            receiveBuffer[rxCount++] = s->DR; // Store received byte
+            bytesToReceive--;
+            // Finish.
+            transactionState = TS_IDLE;
+            completionStatus = I2C_STATUS_OK;
+            state = I2C_STATE_COMPLETED;
+          } else
+            s->SR1 &= I2C_SR1_RXNE;  // Acknowledge interrupt
+        }
+        break;
     }
+    // If we've received an interrupt at any other time, we're not interested so clear it
+    // to prevent it recurring ad infinitum.
+    s->SR1 = 0;
   }
+  
 }
 
 #endif /* I2CMANAGER_STM32_H */

IODevice.h

@@ -22,7 +22,8 @@
 #define iodevice_h
 
 // Define symbol DIAG_IO to enable diagnostic output
-//#define DIAG_IO Y
+//#define DIAG_IO
+
 
 // Define symbol DIAG_LOOPTIMES to enable CS loop execution time to be reported
 //#define DIAG_LOOPTIMES
@@ -409,11 +410,12 @@ private:
   void _begin() override;
   void _loop(unsigned long currentMicros) override;
   int _read(VPIN vpin) override;
-  void _broadcastStatus (VPIN vpin, uint8_t status);
+  void _broadcastStatus (VPIN vpin, uint8_t status, uint8_t activity);
   void _writeAnalogue(VPIN vpin, int value, uint8_t activity, uint16_t duration) override;
   void _display() override;
   uint8_t _stepperStatus;
   uint8_t _previousStatus;
+  uint8_t _currentActivity;
 };
 #endif
 

IO_EXTurntable.cpp

@@ -72,7 +72,9 @@ void EXTurntable::_loop(unsigned long currentMicros) {
   I2CManager.read(_I2CAddress, readBuffer, 1);
   _stepperStatus = readBuffer[0];
   if (_stepperStatus != _previousStatus && _stepperStatus == 0) { // Broadcast when a rotation finishes
-    _broadcastStatus(_firstVpin, _stepperStatus);
+    if ( _currentActivity < 4) {
+      _broadcastStatus(_firstVpin, _stepperStatus, _currentActivity);
+    }
     _previousStatus = _stepperStatus;
   }
   delayUntil(currentMicros + 100000);  // Wait 100ms before checking again
@@ -90,11 +92,13 @@ int EXTurntable::_read(VPIN vpin) {
 }
 
 // If a status change has occurred for a turntable object, broadcast it
-void EXTurntable::_broadcastStatus (VPIN vpin, uint8_t status) {
+void EXTurntable::_broadcastStatus (VPIN vpin, uint8_t status, uint8_t activity) {
   Turntable *tto = Turntable::getByVpin(vpin);
   if (tto) {
-    tto->setMoving(status);
-    CommandDistributor::broadcastTurntable(tto->getId(), tto->getPosition(), status);
+    if (activity < 4) {
+      tto->setMoving(status);
+      CommandDistributor::broadcastTurntable(tto->getId(), tto->getPosition(), status);
+    }
   }
 }
 
@@ -124,9 +128,10 @@ void EXTurntable::_writeAnalogue(VPIN vpin, int value, uint8_t activity, uint16_
   DIAG(F("I2CManager write I2C Address:%d stepsMSB:%d stepsLSB:%d activity:%d"),
     _I2CAddress.toString(), stepsMSB, stepsLSB, activity);
 #endif
-  _stepperStatus = 1;     // Tell the device driver Turntable-EX is busy
+  if (activity < 4) _stepperStatus = 1;     // Tell the device driver Turntable-EX is busy
   _previousStatus = _stepperStatus;
-  _broadcastStatus(vpin, _stepperStatus); // Broadcast when the rotation starts
+  _currentActivity = activity;
+  _broadcastStatus(vpin, _stepperStatus, activity); // Broadcast when the rotation starts
   I2CManager.write(_I2CAddress, 3, stepsMSB, stepsLSB, activity);
 }
 

IO_I2CDFPlayer-test.h

@@ -0,0 +1,825 @@
+   /*
+ *  © 2023, Neil McKechnie. All rights reserved.
+ *  
+ *  This file is part of DCC++EX API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+ * DFPlayer is an MP3 player module with an SD card holder.  It also has an integrated
+ * amplifier, so it only needs a power supply and a speaker.
+ * This driver is a modified version of the IO_DFPlayer.h file
+ * *********************************************************************************************
+ * 
+ * 2023, Added NXP SC16IS752 I2C Dual UART to enable the DFPlayer connection over the I2C bus
+ * The SC16IS752 has 64 bytes TX & RX FIFO buffer
+ * First version without interrupts from I2C UART and only RX/TX are used, interrupts may not be
+ * needed as the RX Fifo holds the reply 
+ * 
+ * myHall.cpp configuration syntax:
+ * 
+ * I2CDFPlayer::create(1st vPin, vPins, I2C address, UART ch, AM);
+ * 
+ * Parameters:
+ * 1st vPin     : First virtual pin that EX-Rail can control to play a sound, use PLAYSOUND command (alias of ANOUT)
+ * vPins        : Total number of virtual pins allocated (only 1 vPin is supported)
+ * I2C Address  : I2C address of the serial controller, in 0x format,
+ * UART ch      : Indicating UART 0 or UART 1, values 0 or 1
+ * AM           : audio mixer, values: 1 or 2 to select an audio amplifier, no effect if AM is not installed
+ * 
+ * The vPin is also an pin that can be read, it indicated if the DFPlayer has finished playing a track
+ *
+ */
+
+#ifndef IO_I2CDFPlayer_h
+#define IO_I2CDFPlayer_h
+
+#include "IODevice.h"
+#include "I2CManager.h"
+#include "DIAG.h"
+
+// Debug and diagnostic defines, enable too many will result in slowing the driver
+//#define DIAG_I2CDFplayer
+//#define DIAG_I2CDFplayer_data
+//#define DIAG_I2CDFplayer_reg
+#define DIAG_I2CDFplayer_playing
+
+class I2CDFPlayer : public IODevice {
+  I2CRB _rb;
+  uint8_t _outbuffer[11]; // common buffer -- test
+  uint8_t _inbuffer[10]; // common buffer -- test
+private: 
+  const uint8_t MAXVOLUME=30;
+  uint8_t RETRYCOUNT = 0x03;
+  bool _playing = false;
+  uint8_t _inputIndex = 0;
+  unsigned long _commandSendTime; // Time (us) that last transmit took place.
+  unsigned long _timeoutTime;
+  uint8_t _recvCMD;  // Last received command code byte
+  bool _awaitingResponse = false;  
+  uint8_t _retryCounter = RETRYCOUNT; // Max retries before timing out
+  uint8_t _requestedVolumeLevel = MAXVOLUME;
+  uint8_t _currentVolume = MAXVOLUME;
+  int _requestedSong = -1;  // -1=none, 0=stop, >0=file number
+  bool _repeat = false; // audio file is repeat playing
+  uint8_t _previousCmd = true;
+  // SC16IS752 defines
+  I2CAddress _I2CAddress;
+  //I2CRB _rb;
+  uint8_t _UART_CH;  
+  // Communication parameters for the DFPlayer are fixed at 8 bit, No parity, 1 stopbit
+  uint8_t WORD_LEN = 0x03;    // Value LCR bit 0,1
+  uint8_t STOP_BIT = 0x00;    // Value LCR bit 2 
+  uint8_t PARITY_ENA = 0x00;  // Value LCR bit 3
+  uint8_t PARITY_TYPE = 0x00; // Value LCR bit 4
+  uint32_t BAUD_RATE = 9600;
+  uint8_t PRESCALER = 0x01;   // Value MCR bit 7
+  uint8_t TEMP_REG_VAL = 0x00;
+  uint8_t FIFO_RX_LEVEL = 0x00;
+  uint8_t RX_BUFFER = 0x00; // nr of bytes copied into _inbuffer
+  uint8_t FIFO_TX_LEVEL = 0x00;  
+  bool _playCmd = false;
+  bool _volCmd = false;
+  bool _folderCmd = false;
+  uint8_t _requestedFolder = 0x01; // default to folder 01
+  uint8_t _currentFolder = 0x01; // default to folder 01
+  bool _repeatCmd = false;
+  bool _stopplayCmd = false;
+  bool _resetCmd = false;
+  bool _eqCmd = false;
+  uint8_t _requestedEQValue = NORMAL;
+  uint8_t _currentEQvalue = NORMAL; // start equalizer value
+  bool _daconCmd = false;
+  uint8_t _audioMixer = 0x01; // Default to output amplifier 1
+  bool _setamCmd = false; // Set the Audio mixer channel
+  //uint8_t _outbuffer[11]; // common buffer -- test
+  //uint8_t _inbuffer[10]; // common buffer -- test
+  uint8_t _outbuffer_0[11]; // DFPlayer command is 10 bytes + 1 byte register address & UART channel -- for UART 0
+  uint8_t _outbuffer_1[11]; // DFPlayer command is 10 bytes + 1 byte register address & UART channel -- for UART 1
+  uint8_t _inbuffer_0[10]; // expected DFPlayer return 10 bytes -- for UART 0
+  uint8_t _inbuffer_1[10]; // expected DFPlayer return 10 bytes -- for UART 1
+ 
+  //unsigned long SC16IS752_XTAL_FREQ = 1843200; // To support cheap eBay/AliExpress SC16IS752 boards
+  unsigned long SC16IS752_XTAL_FREQ = 14745600; // Support for higher baud rates, standard for modular EX-IO system
+
+   
+public:
+  // Constructor
+  I2CDFPlayer(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t UART_CH, uint8_t AM){
+    _firstVpin = firstVpin;
+    _nPins = nPins;
+    _I2CAddress = i2cAddress;
+    _UART_CH = UART_CH;
+    _audioMixer = AM;  
+    addDevice(this);
+   } 
+
+  
+   
+  
+public:
+   static void create(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t UART_CH, uint8_t AM) {
+    if (checkNoOverlap(firstVpin, nPins, i2cAddress)) new I2CDFPlayer(firstVpin, nPins, i2cAddress, UART_CH, AM);
+  }
+
+  void _begin() override {
+    // check if SC16IS752 exist first, initialize and then resume DFPlayer init via SC16IS752
+    I2CManager.begin();
+    I2CManager.setClock(1000000);
+    if (I2CManager.exists(_I2CAddress)){
+      DIAG(F("SC16IS752 I2C:%s UART detected. UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+      Init_SC16IS752(); // Initialize UART
+      if (_deviceState == DEVSTATE_FAILED){
+        DIAG(F("SC16IS752 I2C:%s UART initialization failed, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+        }
+      } else {
+         DIAG(F("SC16IS752 I2C:%s UART not detected, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+        }
+      #if defined(DIAG_IO)
+      _display();
+      #endif
+      // Now init DFPlayer
+      // Send a query to the device to see if it responds
+      _deviceState = DEVSTATE_INITIALISING; 
+      sendPacket(0x42,0,0);
+      _timeoutTime = micros() + 5000000UL;  // 5 second timeout      
+      _awaitingResponse = true; 
+     }
+  
+  
+  void _loop(unsigned long currentMicros) override {
+    // Read responses from device
+    uint8_t status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, so don't do anything
+    if (status == I2C_STATUS_OK) { 
+      processIncoming(currentMicros);
+          // Check if a command sent to device has timed out.  Allow 0.5 second for response
+          // added retry counter, sometimes we do not sent keep alive due to other commands sent to DFPlayer
+      if (_awaitingResponse && (int32_t)(currentMicros - _timeoutTime) > 0) { // timeout triggered
+        if(_retryCounter == 0){ // retry counter out of luck, must take the device to failed state     
+          DIAG(F("I2CDFPlayer:%s, DFPlayer not responding on UART channel: %d"), _I2CAddress.toString(), _UART_CH);
+          _deviceState = DEVSTATE_FAILED;
+          _awaitingResponse = false;
+          _playing = false;
+          _retryCounter = RETRYCOUNT;
+        } else { // timeout and retry protection and recovery of corrupt data frames from DFPlayer
+            #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: %s, DFPlayer timout, retry counter: %d on UART channel: %d"), _I2CAddress.toString(), _retryCounter, _UART_CH);
+            #endif
+            _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds// reset timeout
+            _awaitingResponse = false; // trigger sending a keep alive 0x42 in processOutgoing()
+            _retryCounter --; // decrement retry counter                        
+            resetRX_fifo(); // reset the RX fifo as it has corrupt data            
+          }
+      }      
+    }
+
+    status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, try next time
+    if (status == I2C_STATUS_OK) {
+     // Send any commands that need to go.
+      processOutgoing(currentMicros);
+     }
+    delayUntil(currentMicros + 10000); // Only enter every 10ms    
+  }
+
+ 
+  // Check for incoming data, and update busy flag and other state accordingly
+ 
+  void processIncoming(unsigned long currentMicros) {
+    // Expected message is in the form "7E FF 06 3D xx xx xx xx xx EF"
+    RX_fifo_lvl();
+    if (FIFO_RX_LEVEL >= 10) {      
+      #ifdef DIAG_I2CDFplayer
+        DIAG(F("I2CDFPlayer: %s Retrieving data from RX Fifo on UART_CH: 0x%x FIFO_RX_LEVEL: %d"),_I2CAddress.toString(), _UART_CH, FIFO_RX_LEVEL); 
+      #endif
+      if (_UART_CH == 0){
+        _outbuffer_0[0] = REG_RHR << 3 | _UART_CH << 1;
+        // Only copy 10 bytes from RX FIFO, there maybe additional partial return data after a track is finished playing in the RX FIFO
+        I2CManager.read(_I2CAddress, _inbuffer_0, 10, _outbuffer_0, 1); // inbuffer_0[] has the data now
+        RX_BUFFER = 10; // We have copied 10 bytes from RX FIFO to _inbuffer_0
+         #ifdef DIAG_I2CDFplayer_data
+            DIAG(F("SC16IS752: I2C: %s, Receive data, RX FIFO Data, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+            for (int i = 0; i < sizeof _inbuffer_0; i++){
+              DIAG(F("SC16IS752: Data _inbuffer_0[0x%x]: 0x%x"), i, _inbuffer_0[i]);  
+            }
+          #endif
+      } else if (_UART_CH == 1){
+          _outbuffer_1[0] = REG_RHR << 3 | _UART_CH << 1;
+          // Only copy 10 bytes from RX FIFO, there maybe additional partial return data after a track is finished playing in the RX FIFO
+          I2CManager.read(_I2CAddress, _inbuffer_1, 10, _outbuffer_1, 1); // inbuffer_1[] has the data now
+          RX_BUFFER = 10; // We have copied 10 bytes from RX FIFO to _inbuffer_1
+           #ifdef DIAG_I2CDFplayer_data
+              DIAG(F("SC16IS752: I2C: %s, Receive data, RX FIFO Data, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+              for (int i = 0; i < sizeof _inbuffer_1; i++){
+              DIAG(F("SC16IS752: Data _inbuffer_1[0x%x]: 0x%x"), i, _inbuffer_1[i]);  
+            }
+          #endif
+      }
+    } else {
+        FIFO_RX_LEVEL = 0; //set to 0, we'll read a fresh FIFO_RX_LEVEL next time
+        return; // No data or not enough data in rx fifo, check again next time around
+      }
+
+    // Tranfer _inbuffer_0 or _inbuffer_1 to _inbuffer (this should be a local variable for this instance only)
+    if (_UART_CH==0){
+      for( int i = 0;i < sizeof _inbuffer_0; i++){
+        _inbuffer[i] = _inbuffer_0[i];
+      }      
+    } else if (_UART_CH==1){
+      for( int i = 0;i < sizeof _inbuffer_1; i++){
+        _inbuffer[i] = _inbuffer_1[i];
+      }
+    }
+    
+    bool ok = false;
+    //DIAG(F("I2CDFPlayer: RX_BUFFER: %d"), RX_BUFFER);
+    while (RX_BUFFER != 0) {
+      int c = _inbuffer[_inputIndex]; // Start at 0, increment to FIFO_RX_LEVEL
+      switch (_inputIndex) {
+        case 0:
+          if (c == 0x7E) ok = true;
+          break;
+        case 1:
+          if (c == 0xFF) ok = true;
+          break;
+        case 2:
+          if (c== 0x06) ok = true;
+          break;
+        case 3:
+          _recvCMD = c; // CMD byte
+          ok = true;
+          break;
+        case 6:
+          switch (_recvCMD) {
+            //DIAG(F("I2CDFPlayer: %s, _recvCMD: 0x%x _awaitingResponse: 0x0%x"),_I2CAddress.toString(), _recvCMD, _awaitingResponse);
+            case 0x42:
+              // Response to status query
+              _playing = (c != 0);              
+              // Mark the device online and cancel timeout
+              if (_deviceState==DEVSTATE_INITIALISING) {
+                _deviceState = DEVSTATE_NORMAL;
+                #ifdef DIAG_I2CDFplayer_playing
+                 DIAG(F("I2CDFPlayer: %s, keepalive response: 0x%x, UART_CH: 0x0%x, _deviceState: 0x0%x"),_I2CAddress.toString(), _recvCMD, _UART_CH, _deviceState);
+                #endif 
+                #ifdef DIAG_IO
+                 _display();
+                #endif
+              }
+              #ifdef DIAG_I2CDFplayer_playing
+                DIAG(F("I2CDFPlayer: %s, keepalive response: 0x%x, UART CH: %d"), _I2CAddress.toString(), _recvCMD, _UART_CH);
+              #endif 
+              _awaitingResponse = false;
+              break;
+            case 0x3d:            
+              // End of play
+              if (_playing) {
+                #ifdef DIAG_IO
+                  DIAG(F("I2CDFPlayer: Finished, UART CH: %d"), _UART_CH);
+                #endif
+                _playing = false;
+              }
+              break;
+            case 0x40:
+              // Error codes; 1: Module Busy
+              DIAG(F("I2CDFPlayer: Error %d returned from device, UART CH: %d"), c, _UART_CH);
+              _playing = false;
+              break;
+          }
+          ok = true;
+          break;
+        case 4: case 5: case 7: case 8: 
+          ok = true;  // Skip over these bytes in message.
+          break;
+        case 9:
+          if (c==0xef) {
+            // Message finished
+            _retryCounter = RETRYCOUNT; // reset the retry counter as we have received a valid packet
+          }
+          break;
+        default:
+          break;
+      }
+      if (ok){
+        _inputIndex++;  // character as expected, so increment index
+        RX_BUFFER --; // Decrease FIFO_RX_LEVEL with each character read from _inbuffer[_inputIndex]
+      } else {
+        _inputIndex = 0;  // otherwise reset.
+        RX_BUFFER = 0;
+      }
+    }
+    RX_BUFFER = 0; //Set to 0, we'll read a new RX FIFO level again
+  }
+
+
+  // Send any commands that need to be sent
+  void processOutgoing(unsigned long currentMicros) {
+    // When two commands are sent in quick succession, the device will often fail to 
+    // execute one.  Testing has indicated that a delay of 100ms or more is required
+    // between successive commands to get reliable operation.
+    // If 100ms has elapsed since the last thing sent, then check if there's some output to do.
+    if (((int32_t)currentMicros - _commandSendTime) > 100000) {
+      if ( _resetCmd == true){
+          sendPacket(0x0C,0,0);
+          _resetCmd = false;          
+      } else if(_volCmd == true) { // do the volme before palying a track
+         if(_requestedVolumeLevel >= 0 && _requestedVolumeLevel <= 30){         
+         _currentVolume = _requestedVolumeLevel; // If _requestedVolumeLevel is out of range, sent _currentV1olume      
+         }
+         sendPacket(0x06, 0x00, _currentVolume);
+        _volCmd = false;
+      } else if (_playCmd == true) {
+        // Change song
+        if (_requestedSong != -1) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: _requestedVolumeLevel: %u, _requestedSong: %u, _currentFolder: %u _playCmd: 0x%x"), _requestedVolumeLevel, _requestedSong, _currentFolder, _playCmd);
+          #endif               
+          sendPacket(0x0F, _currentFolder, _requestedSong);  // audio file in folder          
+          _requestedSong = -1; 
+          _playCmd = false;
+        }           
+      } //else if (_requestedSong == 0) {
+        else if (_stopplayCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Stop playing: _stopplayCmd: 0x%x"), _stopplayCmd);
+          #endif
+        sendPacket(0x16, 0x00, 0x00);  // Stop playing        
+        _requestedSong = -1;
+        _repeat = false; // reset repeat        
+        _stopplayCmd = false;
+        } else if (_folderCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Folder: _folderCmd: 0x%x, _requestedFolder: %d"), _stopplayCmd, _requestedFolder);
+          #endif
+          if (_currentFolder != _requestedFolder){
+            _currentFolder = _requestedFolder;
+          }
+          _folderCmd = false;
+      } else if (_repeatCmd == true) {
+        if(_repeat == false) { // No repeat play currently
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Repeat: _repeatCmd: 0x%x, _requestedSong: %d, _repeat: 0x0%x"), _repeatCmd, _requestedSong, _repeat);
+          #endif 
+          sendPacket(0x08, 0x00, _requestedSong);  // repeat playing audio file in root folder          
+          _requestedSong = -1;
+          _repeat = true; 
+        }
+        _repeatCmd= false;      
+      } else if (_daconCmd == true) { // Always turn DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: DACON: _daconCmd: 0x%x"), _daconCmd);
+        #endif 
+        sendPacket(0x1A,0,0x00);
+        _daconCmd = false;
+      } else if (_eqCmd == true){ // Set Equalizer, values 0x00 - 0x05        
+        if (_currentEQvalue != _requestedEQValue){
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: EQ: _eqCmd: 0x%x, _currentEQvalue: 0x0%x, _requestedEQValue: 0x0%x"), _eqCmd, _currentEQvalue, _requestedEQValue);
+          #endif 
+          _currentEQvalue = _requestedEQValue;
+          sendPacket(0x07,0x00,_currentEQvalue);
+        }
+        _eqCmd = false;
+      } else if (_setamCmd == true){ // Set Audio mixer channel
+         setGPIO(); // Set the audio mixer channel
+        _setamCmd = false;        
+      } else if ((int32_t)currentMicros - _commandSendTime > 1000000) {
+        // Poll device every second that other commands aren't being sent,
+        // to check if it's still connected and responding.
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive, UART CH: %d") , _UART_CH);
+          #endif
+        sendPacket(0x42,0,0); 
+        if (!_awaitingResponse) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive, _awaitingResponse: 0x0%x, , UART CH: %d"), _awaitingResponse, _UART_CH);
+          #endif
+          _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds
+          _awaitingResponse = true;
+        }
+      }
+    }  
+  }
+
+
+  // Write to a vPin will do nothing
+  void _write(VPIN vpin, int value) override {
+    if (_deviceState == DEVSTATE_FAILED) return;
+      #ifdef DIAG_IO
+        DIAG(F("I2CDFPlayer: Writing to any vPin not supported"));
+      #endif
+  }
+
+
+  // WriteAnalogue on first pin uses the nominated value as a file number to start playing, if file number > 0.
+  // Volume may be specified as second parameter to writeAnalogue.
+  // If value is zero, the player stops playing.  
+  // WriteAnalogue on second pin sets the output volume.
+  //
+  // WriteAnalogue to be done on first vpin
+  //
+  //void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t=0) override { 
+  void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t cmd=0) override { 
+    if (_deviceState == DEVSTATE_FAILED) return;    
+    #ifdef DIAG_IO
+      DIAG(F("I2CDFPlayer: VPIN:%u FileNo:%d Volume:%d Command:0x%x"), vpin, value, volume, cmd);
+    #endif
+    uint8_t pin = vpin - _firstVpin;
+    if (pin == 0) { // Enhanced DFPlayer commands, do nothing if not vPin 0     
+     // Read command and value
+      switch (cmd){
+       //case NONE:
+       // DFPlayerCmd = cmd;
+       // break;
+       case PLAY:
+        _playCmd = true;
+        _volCmd = true;        
+        _requestedSong = value;
+        _requestedVolumeLevel = volume; 
+        _playing = true;        
+        break;
+        case VOL:
+          _volCmd = true;          
+          _requestedVolumeLevel = volume;
+        break;
+       case FOLDER:
+        _folderCmd = true;
+        if (volume <= 0 || volume > 99){ // Range checking, valid values 1-99, else default to 1
+          _requestedFolder = 0x01; // if outside range, default to folder 01  
+        } else {
+          _requestedFolder = volume;
+        }        
+        break;
+       case REPEATPLAY: // Need to check if _repeat == true, if so do nothing        
+        if (_repeat == false) {
+           #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: WriteAnalog Repeat: _repeat: 0x0%x, value: %d _repeatCmd: 0x%x"), _repeat, value, _repeatCmd);
+           #endif
+          _repeatCmd = true;          
+          _requestedSong = value;
+          _requestedVolumeLevel = volume;
+          _playing = true;         
+        }
+        break;
+       case STOPPLAY:
+        _stopplayCmd = true;        
+        break;
+       case EQ:
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WriteAnalog EQ: cmd: 0x%x, EQ value: 0x%x"), cmd, volume);
+        #endif
+        _eqCmd = true;        
+        if (volume <= 0 || volume > 5) { // If out of range, default to NORMAL
+          _requestedEQValue = NORMAL;            
+        } else { // Valid EQ parameter range
+          _requestedEQValue = volume;     
+          }
+        break;        
+       case RESET:
+        _resetCmd = true;      
+        break; 
+       case DACON: // Works, but without the DACOFF command limited value, except when not relying on DFPlayer default to turn the DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WrtieAnalog DACON: cmd: 0x%x"), cmd);
+        #endif
+        _daconCmd = true;
+        break;
+        case SETAM: // Set the audio mixer channel to 1 or 2
+          _setamCmd = true;
+          #ifdef DIAG_I2CDFplayer_playing
+            DIAG(F("I2CDFPlayer: WrtieAnalog SETAM: value: %d, cmd: 0x%x"), value, cmd);
+          #endif
+          if (volume <= 0 || volume > 2) { // If out of range, default to 1
+            _audioMixer = 1;            
+          } else { // Valid SETAM parameter in range
+              _audioMixer = volume; // _audioMixer valid values 1 or 2
+            }          
+        break;
+       default:
+        break;
+      }
+    }    
+  }
+
+  // A read on any pin indicates if the player is still playing.
+  int _read(VPIN vpin) override {
+    if (_deviceState == DEVSTATE_FAILED) return false;
+    uint8_t pin = vpin - _firstVpin;
+      if (pin == 0) { // Do nothing if not vPin 0
+        return _playing;
+      }
+    }
+
+  void _display() override {
+    DIAG(F("I2CDFPlayer Configured on Vpins:%u-%u %S"), _firstVpin, _firstVpin+_nPins-1,
+      (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
+  }
+  
+private: 
+  // DFPlayer command frame
+  // 7E FF 06 0F 00 01 01 xx xx EF
+  // 0	  ->	7E is start code
+  // 1	  ->	FF is version
+  // 2	  ->	06 is length
+  // 3	  ->	0F is command
+  // 4	  ->	00 is no receive
+  // 5~6	->	01 01 is argument
+  // 7~8	->	checksum = 0 - ( FF+06+0F+00+01+01 )
+  // 9	  ->	EF is end code
+
+  void sendPacket(uint8_t command, uint8_t arg1 = 0, uint8_t arg2 = 0) {
+    FIFO_TX_LEVEL = 0; // Reset FIFO_TX_LEVEL    
+    uint8_t out[] = {
+        0x7E,
+        0xFF,
+        06,
+        command,
+        00,
+        //static_cast<uint8_t>(arg >> 8),
+        //static_cast<uint8_t>(arg & 0x00ff),
+        arg1,
+        arg2,
+        00,
+        00,
+        0xEF };
+
+    setChecksum(out);
+
+      // Prepend the DFPlayer command with REG address and UART Channel in _outbuffer_0 or _outbuffer_1
+      if (_UART_CH==0){
+        _outbuffer_0[0] = REG_THR << 3 | _UART_CH << 1; //TX FIFO and UART Channel      
+        for ( int i = 1; i < sizeof(out)+1 ; i++){
+          _outbuffer_0[i] = out[i-1];
+        }
+      } else if (_UART_CH == 1){
+        _outbuffer_1[0] = REG_THR << 3 | _UART_CH << 1; //TX FIFO and UART Channel      
+        for ( int i = 1; i < sizeof(out)+1 ; i++){
+          _outbuffer_1[i] = out[i-1];
+        }
+       }
+
+      if (_UART_CH==0){
+        #ifdef DIAG_I2CDFplayer_data
+          DIAG(F("SC16IS752: I2C: %s Sent packet function, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+          for (int i = 0; i < sizeof _outbuffer_0; i++){
+            DIAG(F("SC16IS752: Data _outbuffer_0[0x%x]: 0x%x"), i, _outbuffer_0[i]);  
+          }
+        #endif
+      } else if (_UART_CH==1){
+          #ifdef DIAG_I2CDFplayer_data
+            DIAG(F("SC16IS752: I2C: %s Sent packet function, UART CH: %d"), _I2CAddress.toString(), _UART_CH);
+              for (int i = 0; i < sizeof _outbuffer_1; i++){
+                DIAG(F("SC16IS752: Data _outbuffer_1[0x%x]: 0x%x"), i, _outbuffer_1[i]);  
+            }
+          #endif
+      }
+      
+    TX_fifo_lvl();
+    if(FIFO_TX_LEVEL > 0){ //FIFO is empty
+      if (_UART_CH==0){
+        //I2CManager.write(_I2CAddress, _outbuffer_0, sizeof(_outbuffer_0), &_rb); // ************************* use this once buffer issue is solved *********************
+        I2CManager.write(_I2CAddress, _outbuffer_0, sizeof(_outbuffer_0));
+        #ifdef DIAG_I2CDFplayer
+          DIAG(F("SC16IS752: I2C: %s data transmit complete on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+        #endif
+      } else if (_UART_CH==1){
+          //I2CManager.write(_I2CAddress, _outbuffer_1, sizeof(_outbuffer_1), &_rb); // ************************* use this once buffer issue is solved *********************
+          I2CManager.write(_I2CAddress, _outbuffer_1, sizeof(_outbuffer_1));
+          #ifdef DIAG_I2CDFplayer
+           DIAG(F("SC16IS752: I2C: %s data transmit complete on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+          #endif
+        } else {
+           DIAG(F("I2CDFPlayer at: %s, TX FIFO not empty on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+          _deviceState = DEVSTATE_FAILED; // This should not happen
+        }
+      _commandSendTime = micros();
+    } 
+  }
+
+  uint16_t calcChecksum(uint8_t* packet)
+  {
+    uint16_t sum = 0;
+    for (int i = 1; i < 7; i++)
+    {
+      sum += packet[i];
+    }
+    return -sum;
+  }
+
+  void setChecksum(uint8_t* out)
+  {
+    uint16_t sum = calcChecksum(out);
+    out[7] = (sum >> 8);
+    out[8] = (sum & 0xff);
+  }
+
+  // SC16IS752 functions
+  // Initialise SC16IS752 only for this channel
+  // First a software reset
+  // Enable FIFO and clear TX & RX FIFO
+  // Need to set the following registers
+  // IOCONTROL set bit 1 and 2 to 0 indicating that they are GPIO
+  // IODIR set all bit to 1 indicating al are output
+  // IOSTATE set only bit 0 to 1 for UART 0, or only bit 1 for UART 1  // 
+  // LCR bit 7=0 divisor latch (clock division registers DLH & DLL, they store 16 bit divisor), 
+  //     WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE
+  // MCR bit 7=0 clock divisor devide-by-1 clock input
+  // DLH most significant part of divisor
+  // DLL least significant part of divisor
+  //
+  // BAUD_RATE, WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE have been defined and initialized
+  // 
+  void Init_SC16IS752(){ // Return value is in _deviceState
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: Initialize I2C: %s , UART Ch: 0x%x"), _I2CAddress.toString(),  _UART_CH);      
+    #endif
+    uint16_t _divisor = (SC16IS752_XTAL_FREQ / PRESCALER) / (BAUD_RATE * 16);
+    TEMP_REG_VAL = 0x08; // UART Software reset
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set pins to GPIO mode
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0xFF; //Set all pins as output
+    UART_WriteRegister(REG_IODIR, TEMP_REG_VAL);    
+    TEMP_REG_VAL = 0x07; // Reset FIFO, clear RX & TX FIFO
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set MCR to all 0, includes Clock divisor
+    UART_WriteRegister(REG_MCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x80 | WORD_LEN | STOP_BIT | PARITY_ENA | PARITY_TYPE;
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch enabled
+    UART_WriteRegister(REG_DLL, (uint8_t)_divisor);  // Write DLL
+    UART_WriteRegister(REG_DLH, (uint8_t)(_divisor >> 8)); // Write DLH
+    UART_ReadRegister(REG_LCR);
+    TEMP_REG_VAL = _inbuffer[0] & 0x7F; // Disable Divisor latch enabled bit
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch disabled 
+    setGPIO(); // Set the audio mixer channel 
+
+    uint8_t status = _rb.status;
+    if (status != I2C_STATUS_OK) {
+      DIAG(F("SC16IS752: I2C: %s failed %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      _deviceState = DEVSTATE_FAILED;
+    } else {
+      #ifdef DIAG_IO
+       DIAG(F("SC16IS752: I2C: %s, _deviceState: %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      #endif
+     _deviceState = DEVSTATE_NORMAL; // If I2C state is OK, then proceed to initialize DFPlayer 
+    }
+  }
+
+  
+  // Read the Receive FIFO Level register (RXLVL), return a single unsigned integer
+  // of nr of characters in the RX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40) Only display if RX FIFO has data
+  // The RX fifo level is used to check if there are enough bytes to process a frame
+  void RX_fifo_lvl(){
+    UART_ReadRegister(REG_RXLV);
+    FIFO_RX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+     if (FIFO_RX_LEVEL > 0){
+     //if (FIFO_RX_LEVEL > 0 && FIFO_RX_LEVEL < 10){
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_RX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, _inbuffer[0]);
+    }
+    #endif   
+  }
+
+  // When a frame is transmitted from the DFPlayer to the serial port, and at the same time the CS is sending a 42 query
+  // the following two frames from the DFPlayer are corrupt. This result in the receive buffer being out of sync and the 
+  // CS will complain and generate a timeout.
+  // The RX fifo has corrupt data and need to be flushed, this function does that
+  // 
+  void resetRX_fifo(){
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, RX fifo reset"), _I2CAddress.toString(), _UART_CH);
+    #endif    
+    TEMP_REG_VAL = 0x03; // Reset RX fifo
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+  }
+
+  // Set or reset GPIO pin 0 and 1 depending on the UART ch
+  // This function may be modified in a future release to enable all 8 pins to be set or reset with EX-Rail
+  // for various auxilary functions
+  void setGPIO(){
+    UART_ReadRegister(REG_IOSTATE); // Get the current GPIO pins state from the IOSTATE register
+    TEMP_REG_VAL = _inbuffer[0];
+    if (_audioMixer == 1){ // set to audio mixer 1
+      if (_UART_CH == 0){ 
+        TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+      } else { // must be UART 1
+         TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+        }
+    } else { // set to audio mixer 2
+        if (_UART_CH == 0){ 
+          TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 0 to Low
+        } else { // must be UART 1
+           TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 1 to Low
+          }
+      }    
+    UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+    _setamCmd = false;  
+  }
+  
+
+  // Read the Tranmit FIFO Level register (TXLVL), return a single unsigned integer
+  // of nr characters free in the TX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40)
+  //
+  void TX_fifo_lvl(){
+    UART_ReadRegister(REG_TXLV);
+    FIFO_TX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+    //  DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_TX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, FIFO_TX_LEVEL);
+    #endif 
+  }
+
+
+  //void UART_WriteRegister(I2CAddress _I2CAddress, uint8_t _UART_CH, uint8_t UART_REG, uint8_t Val, I2CRB &_rb){
+  void UART_WriteRegister(uint8_t UART_REG, uint8_t Val){
+    _outbuffer[0] = UART_REG << 3 | _UART_CH << 1;
+    _outbuffer[1] = Val;
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Write register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _outbuffer[1]);
+    #endif
+    I2CManager.write(_I2CAddress, _outbuffer, 2);
+  }
+
+ 
+  void UART_ReadRegister(uint8_t UART_REG){
+     _outbuffer[0] = UART_REG << 3 | _UART_CH << 1; // _outbuffer[0] has now UART_REG and UART_CH
+     I2CManager.read(_I2CAddress, _inbuffer, 1, _outbuffer, 1);    
+    // _inbuffer has the REG data
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Read register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _inbuffer[0]);
+    #endif
+  }
+
+// SC16IS752 General register set (from the datasheet)
+enum : uint8_t{
+    REG_RHR       = 0x00, // FIFO Read
+    REG_THR       = 0x00, // FIFO Write
+    REG_IER       = 0x01, // Interrupt Enable Register R/W
+    REG_FCR       = 0x02, // FIFO Control Register Write
+    REG_IIR       = 0x02, // Interrupt Identification Register Read
+    REG_LCR       = 0x03, // Line Control Register R/W
+    REG_MCR       = 0x04, // Modem Control Register R/W
+    REG_LSR       = 0x05, // Line Status Register Read
+    REG_MSR       = 0x06, // Modem Status Register Read
+    REG_SPR       = 0x07, // Scratchpad Register R/W
+    REG_TCR       = 0x06, // Transmission Control Register R/W
+    REG_TLR       = 0x07, // Trigger Level Register R/W    
+    REG_TXLV      = 0x08, // Transmitter FIFO Level register Read
+    REG_RXLV      = 0x09, // Receiver FIFO Level register Read
+    REG_IODIR     = 0x0A, // Programmable I/O pins Direction register R/W
+    REG_IOSTATE   = 0x0B, // Programmable I/O pins State register R/W
+    REG_IOINTENA  = 0x0C, // I/O Interrupt Enable register R/W
+    REG_IOCONTROL = 0x0E, // I/O Control register R/W
+    REG_EFCR      = 0x0F, // Extra Features Control Register R/W
+  };
+
+// SC16IS752 Special register set
+enum : uint8_t{
+    REG_DLL       = 0x00, // Division registers R/W
+    REG_DLH       = 0x01, // Division registers R/W
+  };
+
+// SC16IS752 Enhanced regiter set
+enum : uint8_t{
+    REG_EFR       = 0X02, // Enhanced Features Register R/W
+    REG_XON1      = 0x04, // R/W
+    REG_XON2      = 0x05, // R/W
+    REG_XOFF1     = 0x06, // R/W
+    REG_XOFF2     = 0x07, // R/W
+  };
+
+// DFPlayer commands and values
+enum  : uint8_t{
+    PLAY          = 0x0F,
+    VOL           = 0x06,
+    FOLDER        = 0x2B, // Not a DFPlayer command, used to set folder nr where audio file is
+    REPEATPLAY    = 0x08,
+    STOPPLAY      = 0x16,
+    EQ            = 0x07, // Set equaliser, require parameter NORMAL, POP, ROCK, JAZZ, CLASSIC or BASS
+    RESET         = 0x0C,
+    DACON         = 0x1A,
+    SETAM         = 0x2A, // Set audio mixer 1 or 2 for this DFPLayer   
+    NORMAL        = 0x00, // Equalizer parameters
+    POP           = 0x01,
+    ROCK          = 0x02,
+    JAZZ          = 0x03,
+    CLASSIC       = 0x04,
+    BASS          = 0x05,    
+  };
+
+};
+
+#endif // IO_I2CDFPlayer_h

IO_I2CDFPlayer-test5.h

@@ -0,0 +1,803 @@
+   /*
+ *  © 2023, Neil McKechnie. All rights reserved.
+ *  
+ *  This file is part of DCC++EX API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+ * DFPlayer is an MP3 player module with an SD card holder.  It also has an integrated
+ * amplifier, so it only needs a power supply and a speaker.
+ * This driver is a modified version of the IO_DFPlayer.h file
+ * *********************************************************************************************
+ * 
+ * Dec 2023, Added NXP SC16IS752 I2C Dual UART to enable the DFPlayer connection over the I2C bus
+ * The SC16IS752 has 64 bytes TX & RX FIFO buffer
+ * First version without interrupts from I2C UART and only RX/TX are used, interrupts may not be
+ * needed as the RX Fifo holds the reply 
+ * 
+ * Jan 2024, Issue with using both UARTs simultaniously, the secod uart seems to work  but the first transmit 
+ * corrupt data. This need more analysis and experimenatation. 
+ * Will push this driver to the dev branch with the uart fixed to 0 
+ * Both SC16IS750 (single uart) and SC16IS752 (dual uart, but only uart 0 is enable)
+ * 
+ * myHall.cpp configuration syntax:
+ * 
+ * I2CDFPlayer::create(1st vPin, vPins, I2C address, xtal);
+ * 
+ * Parameters:
+ * 1st vPin     : First virtual pin that EX-Rail can control to play a sound, use PLAYSOUND command (alias of ANOUT)
+ * vPins        : Total number of virtual pins allocated (2 vPins are supported, one for each UART)
+ *                1st vPin for UART 0, 2nd for UART 1
+ * I2C Address  : I2C address of the serial controller, in 0x format
+ * xtal         : 0 for 1,8432Mhz, 1 for 14,7456Mhz
+ * 
+ * The vPin is also a pin that can be read, it indicate if the DFPlayer has finished playing a track
+ *
+ */
+
+#ifndef IO_I2CDFPlayer_h
+#define IO_I2CDFPlayer_h
+
+#include "IODevice.h"
+#include "I2CManager.h"
+#include "DIAG.h"
+
+// Debug and diagnostic defines, enable too many will result in slowing the driver
+//#define DIAG_I2CDFplayer
+//#define DIAG_I2CDFplayer_data
+//#define DIAG_I2CDFplayer_reg
+//#define DIAG_I2CDFplayer_playing
+
+class I2CDFPlayer : public IODevice {
+private: 
+  const uint8_t MAXVOLUME=30;
+  uint8_t RETRYCOUNT = 0x03;
+  bool _playing = false;
+  uint8_t _inputIndex = 0;
+  unsigned long _commandSendTime; // Time (us) that last transmit took place.
+  unsigned long _timeoutTime;
+  uint8_t _recvCMD;  // Last received command code byte
+  bool _awaitingResponse = false;  
+  uint8_t _retryCounter = RETRYCOUNT; // Max retries before timing out
+  uint8_t _requestedVolumeLevel = MAXVOLUME;
+  uint8_t _currentVolume = MAXVOLUME;
+  int _requestedSong = -1;  // -1=none, 0=stop, >0=file number
+  bool _repeat = false; // audio file is repeat playing
+  uint8_t _previousCmd = true;
+  // SC16IS752 defines
+  I2CAddress _I2CAddress;
+  I2CRB _rb;
+  uint8_t _UART_CH=0x00;  // Fix uart ch to 0 for now
+  // Communication parameters for the DFPlayer are fixed at 8 bit, No parity, 1 stopbit
+  uint8_t WORD_LEN = 0x03;    // Value LCR bit 0,1
+  uint8_t STOP_BIT = 0x00;    // Value LCR bit 2 
+  uint8_t PARITY_ENA = 0x00;  // Value LCR bit 3
+  uint8_t PARITY_TYPE = 0x00; // Value LCR bit 4
+  uint32_t BAUD_RATE = 9600;
+  uint8_t PRESCALER = 0x01;   // Value MCR bit 7
+  uint8_t TEMP_REG_VAL = 0x00;
+  uint8_t FIFO_RX_LEVEL = 0x00;
+  uint8_t RX_BUFFER = 0x00; // nr of bytes copied into _inbuffer
+  uint8_t FIFO_TX_LEVEL = 0x00;  
+  bool _playCmd = false;
+  bool _volCmd = false;
+  bool _folderCmd = false;
+  uint8_t _requestedFolder = 0x01; // default to folder 01
+  uint8_t _currentFolder = 0x01; // default to folder 01
+  bool _repeatCmd = false;
+  bool _stopplayCmd = false;
+  bool _resetCmd = false;
+  bool _eqCmd = false;
+  uint8_t _requestedEQValue = NORMAL;
+  uint8_t _currentEQvalue = NORMAL; // start equalizer value
+  bool _daconCmd = false;
+  uint8_t _audioMixer = 0x01; // Default to output amplifier 1
+  bool _setamCmd = false; // Set the Audio mixer channel
+  uint8_t _outbuffer [11]; // DFPlayer command is 10 bytes + 1 byte register address & UART channel
+  uint8_t _inbuffer[10]; // expected DFPlayer return 10 bytes
+   
+  unsigned long _sc16is752_xtal_freq;
+  unsigned long SC16IS752_XTAL_FREQ_LOW = 1843200; // To support cheap eBay/AliExpress SC16IS752 boards
+  unsigned long SC16IS752_XTAL_FREQ_HIGH = 14745600; // Support for higher baud rates, standard for modular EX-IO system
+   
+public:
+  // Constructor
+   I2CDFPlayer(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t xtal){
+    _firstVpin = firstVpin;
+    _nPins = nPins;
+    _I2CAddress = i2cAddress;
+    if (xtal == 0){
+      _sc16is752_xtal_freq = SC16IS752_XTAL_FREQ_LOW;
+    } else { // should be 1
+        _sc16is752_xtal_freq = SC16IS752_XTAL_FREQ_HIGH;
+      }
+    addDevice(this);
+   } 
+  
+public:
+  static void create(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t xtal) {
+    if (checkNoOverlap(firstVpin, nPins, i2cAddress)) new I2CDFPlayer(firstVpin, nPins, i2cAddress, xtal); 
+    }
+
+  void _begin() override {
+    // check if SC16IS752 exist first, initialize and then resume DFPlayer init via SC16IS752
+    I2CManager.begin();
+    I2CManager.setClock(1000000);
+    if (I2CManager.exists(_I2CAddress)){
+      DIAG(F("SC16IS752 I2C:%s UART detected"), _I2CAddress.toString());
+      Init_SC16IS752(); // Initialize UART
+      if (_deviceState == DEVSTATE_FAILED){
+        DIAG(F("SC16IS752 I2C:%s UART initialization failed"), _I2CAddress.toString());
+        }
+      } else {
+         DIAG(F("SC16IS752 I2C:%s UART not detected"), _I2CAddress.toString());
+        }
+      #if defined(DIAG_IO)
+      _display();
+      #endif
+      // Now init DFPlayer
+      // Send a query to the device to see if it responds
+      _deviceState = DEVSTATE_INITIALISING; 
+      sendPacket(0x42,0,0);
+      _timeoutTime = micros() + 5000000UL;  // 5 second timeout      
+      _awaitingResponse = true; 
+     }
+  
+  
+  void _loop(unsigned long currentMicros) override {
+    // Read responses from device
+    uint8_t status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, so don't do anything
+    if (status == I2C_STATUS_OK) { 
+      processIncoming(currentMicros);
+          // Check if a command sent to device has timed out.  Allow 0.5 second for response
+          // added retry counter, sometimes we do not sent keep alive due to other commands sent to DFPlayer
+      if (_awaitingResponse && (int32_t)(currentMicros - _timeoutTime) > 0) { // timeout triggered
+        if(_retryCounter == 0){ // retry counter out of luck, must take the device to failed state     
+          DIAG(F("I2CDFPlayer:%s, DFPlayer not responding on UART channel: 0x%x"), _I2CAddress.toString(), _UART_CH);
+          _deviceState = DEVSTATE_FAILED;
+          _awaitingResponse = false;
+          _playing = false;
+          _retryCounter = RETRYCOUNT;
+        } else { // timeout and retry protection and recovery of corrupt data frames from DFPlayer
+            #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: %s, DFPlayer timout, retry counter: %d on UART channel: 0x%x"), _I2CAddress.toString(), _retryCounter, _UART_CH);
+            #endif
+            _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds// reset timeout
+            _awaitingResponse = false; // trigger sending a keep alive 0x42 in processOutgoing()
+            _retryCounter --; // decrement retry counter                        
+            resetRX_fifo(); // reset the RX fifo as it has corrupt data            
+          }
+      }      
+    }
+
+    status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, try next time
+    if (status == I2C_STATUS_OK) {
+     // Send any commands that need to go.
+      processOutgoing(currentMicros);
+     }
+    delayUntil(currentMicros + 10000); // Only enter every 10ms    
+  }
+
+ 
+  // Check for incoming data, and update busy flag and other state accordingly
+ 
+  void processIncoming(unsigned long currentMicros) {
+    // Expected message is in the form "7E FF 06 3D xx xx xx xx xx EF"
+    RX_fifo_lvl();
+    if (FIFO_RX_LEVEL >= 10) {      
+      #ifdef DIAG_I2CDFplayer
+        DIAG(F("I2CDFPlayer: %s Retrieving data from RX Fifo on UART_CH: 0x%x FIFO_RX_LEVEL: %d"),_I2CAddress.toString(), _UART_CH, FIFO_RX_LEVEL); 
+      #endif
+      _outbuffer[0] = REG_RHR << 3 | _UART_CH << 1;
+      // Only copy 10 bytes from RX FIFO, there maybe additional partial return data after a track is finished playing in the RX FIFO
+      I2CManager.read(_I2CAddress, _inbuffer, 10, _outbuffer, 1); // inbuffer[] has the data now
+      //delayUntil(currentMicros + 10000); // Allow time to get the data
+      RX_BUFFER = 10; // We have copied 10 bytes from RX FIFO to _inbuffer
+        #ifdef DIAG_I2CDFplayer_data
+          DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, RX FIFO Data"), _I2CAddress.toString(), _UART_CH);
+          for (int i = 0; i < sizeof _inbuffer; i++){
+            DIAG(F("SC16IS752: Data _inbuffer[0x%x]: 0x%x"), i, _inbuffer[i]);  
+          }
+        #endif       
+    } else {
+        FIFO_RX_LEVEL = 0; //set to 0, we'll read a fresh FIFO_RX_LEVEL next time
+        return; // No data or not enough data in rx fifo, check again next time around
+      }
+
+    
+    bool ok = false;
+    //DIAG(F("I2CDFPlayer: RX_BUFFER: %d"), RX_BUFFER);
+    while (RX_BUFFER != 0) {
+      int c = _inbuffer[_inputIndex]; // Start at 0, increment to FIFO_RX_LEVEL
+      switch (_inputIndex) {
+        case 0:
+          if (c == 0x7E) ok = true;
+          break;
+        case 1:
+          if (c == 0xFF) ok = true;
+          break;
+        case 2:
+          if (c== 0x06) ok = true;
+          break;
+        case 3:
+          _recvCMD = c; // CMD byte
+          ok = true;
+          break;
+        case 6:
+          switch (_recvCMD) {
+            //DIAG(F("I2CDFPlayer: %s, _recvCMD: 0x%x _awaitingResponse: 0x0%x"),_I2CAddress.toString(), _recvCMD, _awaitingResponse);
+            case 0x42:
+              // Response to status query
+              _playing = (c != 0);              
+              // Mark the device online and cancel timeout
+              if (_deviceState==DEVSTATE_INITIALISING) {
+                _deviceState = DEVSTATE_NORMAL;
+                #ifdef DIAG_I2CDFplayer
+                 DIAG(F("I2CDFPlayer: %s, UART_CH: 0x0%x, _deviceState: 0x0%x"),_I2CAddress.toString(), _UART_CH, _deviceState);
+                #endif 
+                #ifdef DIAG_IO
+                _display();
+                #endif
+              }
+              _awaitingResponse = false;
+              break;
+            case 0x3d:            
+              // End of play
+              if (_playing) {
+                #ifdef DIAG_IO
+                  DIAG(F("I2CDFPlayer: Finished"));
+                #endif
+                _playing = false;
+              }
+              break;
+            case 0x40:
+              // Error codes; 1: Module Busy
+              DIAG(F("I2CDFPlayer: Error %d returned from device"), c);
+              _playing = false;
+              break;
+          }
+          ok = true;
+          break;
+        case 4: case 5: case 7: case 8: 
+          ok = true;  // Skip over these bytes in message.
+          break;
+        case 9:
+          if (c==0xef) {
+            // Message finished
+            _retryCounter = RETRYCOUNT; // reset the retry counter as we have received a valid packet
+          }
+          break;
+        default:
+          break;
+      }
+      if (ok){
+        _inputIndex++;  // character as expected, so increment index
+        RX_BUFFER --; // Decrease FIFO_RX_LEVEL with each character read from _inbuffer[_inputIndex]
+      } else {
+        _inputIndex = 0;  // otherwise reset.
+        RX_BUFFER = 0;
+      }
+    }
+    RX_BUFFER = 0; //Set to 0, we'll read a new RX FIFO level again
+  }
+
+
+  // Send any commands that need to be sent
+  void processOutgoing(unsigned long currentMicros) {
+    // When two commands are sent in quick succession, the device will often fail to 
+    // execute one.  Testing has indicated that a delay of 100ms or more is required
+    // between successive commands to get reliable operation.
+    // If 100ms has elapsed since the last thing sent, then check if there's some output to do.
+    if (((int32_t)currentMicros - _commandSendTime) > 100000) {
+      if ( _resetCmd == true){
+          sendPacket(0x0C,0,0);
+          _resetCmd = false;          
+      } else if(_volCmd == true) { // do the volme before palying a track
+         if(_requestedVolumeLevel >= 0 && _requestedVolumeLevel <= 30){         
+         _currentVolume = _requestedVolumeLevel; // If _requestedVolumeLevel is out of range, sent _currentV1olume      
+         }
+         sendPacket(0x06, 0x00, _currentVolume);
+        _volCmd = false;
+      } else if (_playCmd == true) {
+        // Change song
+        if (_requestedSong != -1) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: _requestedVolumeLevel: %u, _requestedSong: %u, _currentFolder: %u _playCmd: 0x%x"), _requestedVolumeLevel, _requestedSong, _currentFolder, _playCmd);
+          #endif               
+          sendPacket(0x0F, _currentFolder, _requestedSong);  // audio file in folder          
+          _requestedSong = -1; 
+          _playCmd = false;
+        }           
+      } //else if (_requestedSong == 0) {
+        else if (_stopplayCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Stop playing: _stopplayCmd: 0x%x"), _stopplayCmd);
+          #endif
+        sendPacket(0x16, 0x00, 0x00);  // Stop playing        
+        _requestedSong = -1;
+        _repeat = false; // reset repeat        
+        _stopplayCmd = false;
+        } else if (_folderCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Folder: _folderCmd: 0x%x, _requestedFolder: %d"), _stopplayCmd, _requestedFolder);
+          #endif
+          if (_currentFolder != _requestedFolder){
+            _currentFolder = _requestedFolder;
+          }
+          _folderCmd = false;
+      } else if (_repeatCmd == true) {
+        if(_repeat == false) { // No repeat play currently
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Repeat: _repeatCmd: 0x%x, _requestedSong: %d, _repeat: 0x0%x"), _repeatCmd, _requestedSong, _repeat);
+          #endif 
+          sendPacket(0x08, 0x00, _requestedSong);  // repeat playing audio file in root folder          
+          _requestedSong = -1;
+          _repeat = true; 
+        }
+        _repeatCmd= false;      
+      } else if (_daconCmd == true) { // Always turn DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: DACON: _daconCmd: 0x%x"), _daconCmd);
+        #endif 
+        sendPacket(0x1A,0,0x00);
+        _daconCmd = false;
+      } else if (_eqCmd == true){ // Set Equalizer, values 0x00 - 0x05        
+        if (_currentEQvalue != _requestedEQValue){
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: EQ: _eqCmd: 0x%x, _currentEQvalue: 0x0%x, _requestedEQValue: 0x0%x"), _eqCmd, _currentEQvalue, _requestedEQValue);
+          #endif 
+          _currentEQvalue = _requestedEQValue;
+          sendPacket(0x07,0x00,_currentEQvalue);
+        }
+        _eqCmd = false;
+      } else if (_setamCmd == true){ // Set Audio mixer channel
+         setGPIO(); // Set the audio mixer channel
+         /*        
+          if (_audioMixer == 1){ // set to audio mixer 1       
+            if (_UART_CH == 0){ 
+              TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+            } else { // must be UART 1
+              TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+              }
+           //_setamCmd = false;
+           //UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+          } else { // set to audio mixer 2
+              if (_UART_CH == 0){ 
+                TEMP_REG_VAL &= (0x00 << _UART_CH); //Set GPIO pin 0 to Low
+              } else { // must be UART 1
+                TEMP_REG_VAL &= (0x00 << _UART_CH); //Set GPIO pin 1 to Low
+                }
+              //_setamCmd = false;
+              //UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+            }*/
+        _setamCmd = false;        
+      } else if ((int32_t)currentMicros - _commandSendTime > 1000000) {
+        // Poll device every second that other commands aren't being sent,
+        // to check if it's still connected and responding.
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive") );
+          #endif
+        sendPacket(0x42,0,0); 
+        if (!_awaitingResponse) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive, _awaitingResponse: 0x0%x"), _awaitingResponse );
+          #endif
+          _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds
+          _awaitingResponse = true;
+        }
+      }
+    }  
+  }
+
+
+  // Write to a vPin will do nothing
+  void _write(VPIN vpin, int value) override {
+    if (_deviceState == DEVSTATE_FAILED) return;
+      #ifdef DIAG_IO
+        DIAG(F("I2CDFPlayer: Writing to any vPin not supported"));
+      #endif
+  }
+
+
+  // WriteAnalogue on first pin uses the nominated value as a file number to start playing, if file number > 0.
+  // Volume may be specified as second parameter to writeAnalogue.
+  // If value is zero, the player stops playing.  
+  // WriteAnalogue on second pin sets the output volume.
+  //
+  // WriteAnalogue to be done on first vpin
+  //
+  //void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t=0) override { 
+  void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t cmd=0) override { 
+    if (_deviceState == DEVSTATE_FAILED) return;    
+    #ifdef DIAG_IO
+      DIAG(F("I2CDFPlayer: VPIN:%u FileNo:%d Volume:%d Command:0x%x"), vpin, value, volume, cmd);
+    #endif
+    uint8_t pin = vpin - _firstVpin;
+    if (pin == 0) { // Enhanced DFPlayer commands, do nothing if not vPin 0     
+     // Read command and value
+      switch (cmd){
+       //case NONE:
+       // DFPlayerCmd = cmd;
+       // break;
+       case PLAY:
+        _playCmd = true;
+        _volCmd = true;        
+        _requestedSong = value;
+        _requestedVolumeLevel = volume; 
+        _playing = true;        
+        break;
+        case VOL:
+          _volCmd = true;          
+          _requestedVolumeLevel = volume;
+        break;
+       case FOLDER:
+        _folderCmd = true;
+        if (volume <= 0 || volume > 99){ // Range checking, valid values 1-99, else default to 1
+          _requestedFolder = 0x01; // if outside range, default to folder 01  
+        } else {
+          _requestedFolder = volume;
+        }        
+        break;
+       case REPEATPLAY: // Need to check if _repeat == true, if so do nothing        
+        if (_repeat == false) {
+           #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: WriteAnalog Repeat: _repeat: 0x0%x, value: %d _repeatCmd: 0x%x"), _repeat, value, _repeatCmd);
+           #endif
+          _repeatCmd = true;          
+          _requestedSong = value;
+          _requestedVolumeLevel = volume;
+          _playing = true;         
+        }
+        break;
+       case STOPPLAY:
+        _stopplayCmd = true;        
+        break;
+       case EQ:
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WriteAnalog EQ: cmd: 0x%x, EQ value: 0x%x"), cmd, volume);
+        #endif
+        _eqCmd = true;        
+        if (volume <= 0 || volume > 5) { // If out of range, default to NORMAL
+          _requestedEQValue = NORMAL;            
+        } else { // Valid EQ parameter range
+          _requestedEQValue = volume;     
+          }
+        break;        
+       case RESET:
+        _resetCmd = true;      
+        break; 
+       case DACON: // Works, but without the DACOFF command limited value, except when not relying on DFPlayer default to turn the DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WrtieAnalog DACON: cmd: 0x%x"), cmd);
+        #endif
+        _daconCmd = true;
+        break;
+        case SETAM: // Set the audio mixer channel to 1 or 2
+          _setamCmd = true;
+          #ifdef DIAG_I2CDFplayer_playing
+            DIAG(F("I2CDFPlayer: WrtieAnalog SETAM: cmd: 0x%x"), cmd);
+          #endif
+          if (volume <= 0 || volume > 2) { // If out of range, default to 1
+            _audioMixer = 1;            
+          } else { // Valid SETAM parameter in range
+              _audioMixer = volume; // _audioMixer valid values 1 or 2
+            }          
+        break;
+       default:
+        break;
+      }
+    }    
+  }
+
+  // A read on any pin indicates if the player is still playing.
+  int _read(VPIN vpin) override {
+    if (_deviceState == DEVSTATE_FAILED) return false;
+    uint8_t pin = vpin - _firstVpin;
+      if (pin == 0) { // Do nothing if not vPin 0
+        return _playing;
+      }
+    }
+
+  void _display() override {
+    DIAG(F("I2CDFPlayer Configured on Vpins:%u-%u %S"), _firstVpin, _firstVpin+_nPins-1,
+      (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
+  }
+  
+private: 
+  // DFPlayer command frame
+  // 7E FF 06 0F 00 01 01 xx xx EF
+  // 0	  ->	7E is start code
+  // 1	  ->	FF is version
+  // 2	  ->	06 is length
+  // 3	  ->	0F is command
+  // 4	  ->	00 is no receive
+  // 5~6	->	01 01 is argument
+  // 7~8	->	checksum = 0 - ( FF+06+0F+00+01+01 )
+  // 9	  ->	EF is end code
+
+  void sendPacket(uint8_t command, uint8_t arg1 = 0, uint8_t arg2 = 0) {
+    FIFO_TX_LEVEL = 0; // Reset FIFO_TX_LEVEL    
+    uint8_t out[] = {
+        0x7E,
+        0xFF,
+        06,
+        command,
+        00,
+        //static_cast<uint8_t>(arg >> 8),
+        //static_cast<uint8_t>(arg & 0x00ff),
+        arg1,
+        arg2,
+        00,
+        00,
+        0xEF };
+
+    setChecksum(out);
+
+      // Prepend the DFPlayer command with REG address and UART Channel in _outbuffer
+      _outbuffer[0] = REG_THR << 3 | _UART_CH << 1; //TX FIFO and UART Channel      
+      for ( int i = 1; i < sizeof(out)+1 ; i++){
+        _outbuffer[i] = out[i-1];
+      }
+
+      #ifdef DIAG_I2CDFplayer_data
+       DIAG(F("SC16IS752: I2C: %s Sent packet function"), _I2CAddress.toString());
+       for (int i = 0; i < sizeof _outbuffer; i++){
+        DIAG(F("SC16IS752: Data _outbuffer[0x%x]: 0x%x"), i, _outbuffer[i]);  
+       }
+      #endif
+      
+    TX_fifo_lvl();
+    if(FIFO_TX_LEVEL > 0){ //FIFO is empty
+      I2CManager.write(_I2CAddress, _outbuffer, sizeof(_outbuffer), &_rb);
+      //I2CManager.write(_I2CAddress, _outbuffer, sizeof(_outbuffer));
+      #ifdef DIAG_I2CDFplayer
+       DIAG(F("SC16IS752: I2C: %s data transmit complete on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+      #endif
+    } else {
+      DIAG(F("I2CDFPlayer at: %s, TX FIFO not empty on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+      _deviceState = DEVSTATE_FAILED; // This should not happen      
+    }
+    _commandSendTime = micros();
+  }
+
+  uint16_t calcChecksum(uint8_t* packet)
+  {
+    uint16_t sum = 0;
+    for (int i = 1; i < 7; i++)
+    {
+      sum += packet[i];
+    }
+    return -sum;
+  }
+
+  void setChecksum(uint8_t* out)
+  {
+    uint16_t sum = calcChecksum(out);
+    out[7] = (sum >> 8);
+    out[8] = (sum & 0xff);
+  }
+
+  // SC16IS752 functions
+  // Initialise SC16IS752 only for this channel
+  // First a software reset
+  // Enable FIFO and clear TX & RX FIFO
+  // Need to set the following registers
+  // IOCONTROL set bit 1 and 2 to 0 indicating that they are GPIO
+  // IODIR set all bit to 1 indicating al are output
+  // IOSTATE set only bit 0 to 1 for UART 0, or only bit 1 for UART 1  // 
+  // LCR bit 7=0 divisor latch (clock division registers DLH & DLL, they store 16 bit divisor), 
+  //     WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE
+  // MCR bit 7=0 clock divisor devide-by-1 clock input
+  // DLH most significant part of divisor
+  // DLL least significant part of divisor
+  //
+  // BAUD_RATE, WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE have been defined and initialized
+  // 
+  void Init_SC16IS752(){ // Return value is in _deviceState
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: Initialize I2C: %s , UART Ch: 0x%x"), _I2CAddress.toString(),  _UART_CH);      
+    #endif
+    //uint16_t _divisor = (SC16IS752_XTAL_FREQ / PRESCALER) / (BAUD_RATE * 16);
+    uint16_t _divisor = (_sc16is752_xtal_freq/PRESCALER)/(BAUD_RATE * 16);  // Calculate _divisor for baudrate
+    TEMP_REG_VAL = 0x08; // UART Software reset
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set pins to GPIO mode
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0xFF; //Set all pins as output
+    UART_WriteRegister(REG_IODIR, TEMP_REG_VAL);
+    UART_ReadRegister(REG_IOSTATE); // Read current state as not to overwrite the other GPIO pins
+    TEMP_REG_VAL = _inbuffer[0];
+    setGPIO(); // Set the audio mixer channel
+    /*
+    if (_UART_CH == 0){ // Set Audio mixer channel
+      TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+    } else { // must be UART 1
+      TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+    }
+    UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+    */
+    TEMP_REG_VAL = 0x07; // Reset FIFO, clear RX & TX FIFO
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set MCR to all 0, includes Clock divisor
+    UART_WriteRegister(REG_MCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x80 | WORD_LEN | STOP_BIT | PARITY_ENA | PARITY_TYPE;
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch enabled
+    UART_WriteRegister(REG_DLL, (uint8_t)_divisor);  // Write DLL
+    UART_WriteRegister(REG_DLH, (uint8_t)(_divisor >> 8)); // Write DLH
+    UART_ReadRegister(REG_LCR);
+    TEMP_REG_VAL = _inbuffer[0] & 0x7F; // Disable Divisor latch enabled bit
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch disabled  
+
+    uint8_t status = _rb.status;
+    if (status != I2C_STATUS_OK) {
+      DIAG(F("SC16IS752: I2C: %s failed %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      _deviceState = DEVSTATE_FAILED;
+    } else {
+      #ifdef DIAG_IO
+       DIAG(F("SC16IS752: I2C: %s, _deviceState: %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      #endif
+     _deviceState = DEVSTATE_NORMAL; // If I2C state is OK, then proceed to initialize DFPlayer 
+    }
+  }
+
+  
+  // Read the Receive FIFO Level register (RXLVL), return a single unsigned integer
+  // of nr of characters in the RX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40) Only display if RX FIFO has data
+  // The RX fifo level is used to check if there are enough bytes to process a frame
+  void RX_fifo_lvl(){
+    UART_ReadRegister(REG_RXLV);
+    FIFO_RX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+     if (FIFO_RX_LEVEL > 0){
+     //if (FIFO_RX_LEVEL > 0 && FIFO_RX_LEVEL < 10){
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_RX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, _inbuffer[0]);
+    }
+    #endif   
+  }
+
+  // When a frame is transmitted from the DFPlayer to the serial port, and at the same time the CS is sending a 42 query
+  // the following two frames from the DFPlayer are corrupt. This result in the receive buffer being out of sync and the 
+  // CS will complain and generate a timeout.
+  // The RX fifo has corrupt data and need to be flushed, this function does that
+  // 
+  void resetRX_fifo(){
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, RX fifo reset"), _I2CAddress.toString(), _UART_CH);
+    #endif    
+    TEMP_REG_VAL = 0x03; // Reset RX fifo
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+  }
+
+  // Set or reset GPIO pin 0 and 1 depending on the UART ch
+  // This function may be modified in a future release to enable all 8 pins to be set or reset with EX-Rail
+  // for various auxilary functions
+  void setGPIO(){
+    UART_ReadRegister(REG_IOSTATE); // Get the current GPIO pins state from the IOSTATE register
+    TEMP_REG_VAL = _inbuffer[0];
+    if (_audioMixer == 1){ // set to audio mixer 1
+      if (_UART_CH == 0){ 
+        TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+      } else { // must be UART 1
+         TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+        }
+    } else { // set to audio mixer 2
+        if (_UART_CH == 0){ 
+          TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 0 to Low
+        } else { // must be UART 1
+           TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 1 to Low
+          }
+      }    
+    UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+    _setamCmd = false;  
+  }
+  
+
+  // Read the Tranmit FIFO Level register (TXLVL), return a single unsigned integer
+  // of nr characters free in the TX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40)
+  //
+  void TX_fifo_lvl(){
+    UART_ReadRegister(REG_TXLV);
+    FIFO_TX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+    //  DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_TX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, FIFO_TX_LEVEL);
+    #endif 
+  }
+
+
+  //void UART_WriteRegister(I2CAddress _I2CAddress, uint8_t _UART_CH, uint8_t UART_REG, uint8_t Val, I2CRB &_rb){
+  void UART_WriteRegister(uint8_t UART_REG, uint8_t Val){
+    _outbuffer[0] = UART_REG << 3 | _UART_CH << 1;
+    _outbuffer[1] = Val;
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Write register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _outbuffer[1]);
+    #endif
+    I2CManager.write(_I2CAddress, _outbuffer, 2);
+  }
+
+ 
+  void UART_ReadRegister(uint8_t UART_REG){
+     _outbuffer[0] = UART_REG << 3 | _UART_CH << 1; // _outbuffer[0] has now UART_REG and UART_CH
+     I2CManager.read(_I2CAddress, _inbuffer, 1, _outbuffer, 1);    
+    // _inbuffer has the REG data
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Read register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _inbuffer[0]);
+    #endif
+  }
+
+// SC16IS752 General register set (from the datasheet)
+enum : uint8_t{
+    REG_RHR       = 0x00, // FIFO Read
+    REG_THR       = 0x00, // FIFO Write
+    REG_IER       = 0x01, // Interrupt Enable Register R/W
+    REG_FCR       = 0x02, // FIFO Control Register Write
+    REG_IIR       = 0x02, // Interrupt Identification Register Read
+    REG_LCR       = 0x03, // Line Control Register R/W
+    REG_MCR       = 0x04, // Modem Control Register R/W
+    REG_LSR       = 0x05, // Line Status Register Read
+    REG_MSR       = 0x06, // Modem Status Register Read
+    REG_SPR       = 0x07, // Scratchpad Register R/W
+    REG_TCR       = 0x06, // Transmission Control Register R/W
+    REG_TLR       = 0x07, // Trigger Level Register R/W    
+    REG_TXLV      = 0x08, // Transmitter FIFO Level register Read
+    REG_RXLV      = 0x09, // Receiver FIFO Level register Read
+    REG_IODIR     = 0x0A, // Programmable I/O pins Direction register R/W
+    REG_IOSTATE   = 0x0B, // Programmable I/O pins State register R/W
+    REG_IOINTENA  = 0x0C, // I/O Interrupt Enable register R/W
+    REG_IOCONTROL = 0x0E, // I/O Control register R/W
+    REG_EFCR      = 0x0F, // Extra Features Control Register R/W
+  };
+
+// SC16IS752 Special register set
+enum : uint8_t{
+    REG_DLL       = 0x00, // Division registers R/W
+    REG_DLH       = 0x01, // Division registers R/W
+  };
+
+// SC16IS752 Enhanced regiter set
+enum : uint8_t{
+    REG_EFR       = 0X02, // Enhanced Features Register R/W
+    REG_XON1      = 0x04, // R/W
+    REG_XON2      = 0x05, // R/W
+    REG_XOFF1     = 0x06, // R/W
+    REG_XOFF2     = 0x07, // R/W
+  };
+
+// DFPlayer commands and values
+enum  : uint8_t{
+    PLAY          = 0x0F,
+    VOL           = 0x06,
+    FOLDER        = 0x2B, // Not a DFPlayer command, used to set folder nr where audio file is
+    REPEATPLAY    = 0x08,
+    STOPPLAY      = 0x16,
+    EQ            = 0x07, // Set equaliser, require parameter NORMAL, POP, ROCK, JAZZ, CLASSIC or BASS
+    RESET         = 0x0C,
+    DACON         = 0x1A,
+    SETAM         = 0x2A, // Set audio mixer 1 or 2 for this DFPLayer   
+    NORMAL        = 0x00, // Equalizer parameters
+    POP           = 0x01,
+    ROCK          = 0x02,
+    JAZZ          = 0x03,
+    CLASSIC       = 0x04,
+    BASS          = 0x05,    
+  };
+
+};
+
+#endif // IO_I2CDFPlayer_h

IO_I2CDFPlayer.h

@@ -0,0 +1,794 @@
+   /*
+ *  © 2023, Neil McKechnie. All rights reserved.
+ *  
+ *  This file is part of DCC++EX API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+ * DFPlayer is an MP3 player module with an SD card holder.  It also has an integrated
+ * amplifier, so it only needs a power supply and a speaker.
+ * This driver is a modified version of the IO_DFPlayer.h file
+ * *********************************************************************************************
+ * 
+ * 2023, Added NXP SC16IS752 I2C Dual UART to enable the DFPlayer connection over the I2C bus
+ * The SC16IS752 has 64 bytes TX & RX FIFO buffer
+ * First version without interrupts from I2C UART and only RX/TX are used, interrupts may not be
+ * needed as the RX Fifo holds the reply 
+ * 
+ * myHall.cpp configuration syntax:
+ * 
+ * I2CDFPlayer::create(1st vPin, vPins, I2C address, UART ch, AM);
+ * 
+ * Parameters:
+ * 1st vPin     : First virtual pin that EX-Rail can control to play a sound, use PLAYSOUND command (alias of ANOUT)
+ * vPins        : Total number of virtual pins allocated (only 1 vPin is supported)
+ * I2C Address  : I2C address of the serial controller, in 0x format,
+ * UART ch      : Indicating UART 0 or UART 1, values 0 or 1
+ * AM           : audio mixer, values: 1 or 2 to select an audio amplifier, no effect if AM is not installed
+ * 
+ * The vPin is also an pin that can be read, it indicated if the DFPlayer has finished playing a track
+ *
+ */
+
+#ifndef IO_I2CDFPlayer_h
+#define IO_I2CDFPlayer_h
+
+#include "IODevice.h"
+#include "I2CManager.h"
+#include "DIAG.h"
+
+// Debug and diagnostic defines, enable too many will result in slowing the driver
+//#define DIAG_I2CDFplayer
+//#define DIAG_I2CDFplayer_data
+//#define DIAG_I2CDFplayer_reg
+//#define DIAG_I2CDFplayer_playing
+
+class I2CDFPlayer : public IODevice {
+private: 
+  const uint8_t MAXVOLUME=30;
+  uint8_t RETRYCOUNT = 0x03;
+  bool _playing = false;
+  uint8_t _inputIndex = 0;
+  unsigned long _commandSendTime; // Time (us) that last transmit took place.
+  unsigned long _timeoutTime;
+  uint8_t _recvCMD;  // Last received command code byte
+  bool _awaitingResponse = false;  
+  uint8_t _retryCounter = RETRYCOUNT; // Max retries before timing out
+  uint8_t _requestedVolumeLevel = MAXVOLUME;
+  uint8_t _currentVolume = MAXVOLUME;
+  int _requestedSong = -1;  // -1=none, 0=stop, >0=file number
+  bool _repeat = false; // audio file is repeat playing
+  uint8_t _previousCmd = true;
+  // SC16IS752 defines
+  I2CAddress _I2CAddress;
+  I2CRB _rb;
+  uint8_t _UART_CH;  
+  // Communication parameters for the DFPlayer are fixed at 8 bit, No parity, 1 stopbit
+  uint8_t WORD_LEN = 0x03;    // Value LCR bit 0,1
+  uint8_t STOP_BIT = 0x00;    // Value LCR bit 2 
+  uint8_t PARITY_ENA = 0x00;  // Value LCR bit 3
+  uint8_t PARITY_TYPE = 0x00; // Value LCR bit 4
+  uint32_t BAUD_RATE = 9600;
+  uint8_t PRESCALER = 0x01;   // Value MCR bit 7
+  uint8_t TEMP_REG_VAL = 0x00;
+  uint8_t FIFO_RX_LEVEL = 0x00;
+  uint8_t RX_BUFFER = 0x00; // nr of bytes copied into _inbuffer
+  uint8_t FIFO_TX_LEVEL = 0x00;  
+  bool _playCmd = false;
+  bool _volCmd = false;
+  bool _folderCmd = false;
+  uint8_t _requestedFolder = 0x01; // default to folder 01
+  uint8_t _currentFolder = 0x01; // default to folder 01
+  bool _repeatCmd = false;
+  bool _stopplayCmd = false;
+  bool _resetCmd = false;
+  bool _eqCmd = false;
+  uint8_t _requestedEQValue = NORMAL;
+  uint8_t _currentEQvalue = NORMAL; // start equalizer value
+  bool _daconCmd = false;
+  uint8_t _audioMixer = 0x01; // Default to output amplifier 1
+  bool _setamCmd = false; // Set the Audio mixer channel
+  uint8_t _outbuffer [11]; // DFPlayer command is 10 bytes + 1 byte register address & UART channel
+  uint8_t _inbuffer[10]; // expected DFPlayer return 10 bytes
+ 
+  //unsigned long SC16IS752_XTAL_FREQ = 1843200; // To support cheap eBay/AliExpress SC16IS752 boards
+  unsigned long SC16IS752_XTAL_FREQ = 14745600; // Support for higher baud rates, standard for modular EX-IO system
+
+   
+public:
+  // Constructor
+  I2CDFPlayer(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t UART_CH, uint8_t AM){
+    _firstVpin = firstVpin;
+    _nPins = nPins;
+    _I2CAddress = i2cAddress;
+    _UART_CH = UART_CH;
+    _audioMixer = AM;  
+    addDevice(this);
+   } 
+  
+public:
+   static void create(VPIN firstVpin, int nPins, I2CAddress i2cAddress, uint8_t UART_CH, uint8_t AM) {
+    if (checkNoOverlap(firstVpin, nPins, i2cAddress)) new I2CDFPlayer(firstVpin, nPins, i2cAddress, UART_CH, AM);
+  }
+
+  void _begin() override {
+    // check if SC16IS752 exist first, initialize and then resume DFPlayer init via SC16IS752
+    I2CManager.begin();
+    I2CManager.setClock(1000000);
+    if (I2CManager.exists(_I2CAddress)){
+      DIAG(F("SC16IS752 I2C:%s UART detected"), _I2CAddress.toString());
+      Init_SC16IS752(); // Initialize UART
+      if (_deviceState == DEVSTATE_FAILED){
+        DIAG(F("SC16IS752 I2C:%s UART initialization failed"), _I2CAddress.toString());
+        }
+      } else {
+         DIAG(F("SC16IS752 I2C:%s UART not detected"), _I2CAddress.toString());
+        }
+      #if defined(DIAG_IO)
+      _display();
+      #endif
+      // Now init DFPlayer
+      // Send a query to the device to see if it responds
+      _deviceState = DEVSTATE_INITIALISING; 
+      sendPacket(0x42,0,0);
+      _timeoutTime = micros() + 5000000UL;  // 5 second timeout      
+      _awaitingResponse = true; 
+     }
+  
+  
+  void _loop(unsigned long currentMicros) override {
+    // Read responses from device
+    uint8_t status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, so don't do anything
+    if (status == I2C_STATUS_OK) { 
+      processIncoming(currentMicros);
+          // Check if a command sent to device has timed out.  Allow 0.5 second for response
+          // added retry counter, sometimes we do not sent keep alive due to other commands sent to DFPlayer
+      if (_awaitingResponse && (int32_t)(currentMicros - _timeoutTime) > 0) { // timeout triggered
+        if(_retryCounter == 0){ // retry counter out of luck, must take the device to failed state     
+          DIAG(F("I2CDFPlayer:%s, DFPlayer not responding on UART channel: 0x%x"), _I2CAddress.toString(), _UART_CH);
+          _deviceState = DEVSTATE_FAILED;
+          _awaitingResponse = false;
+          _playing = false;
+          _retryCounter = RETRYCOUNT;
+        } else { // timeout and retry protection and recovery of corrupt data frames from DFPlayer
+            #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: %s, DFPlayer timout, retry counter: %d on UART channel: 0x%x"), _I2CAddress.toString(), _retryCounter, _UART_CH);
+            #endif
+            _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds// reset timeout
+            _awaitingResponse = false; // trigger sending a keep alive 0x42 in processOutgoing()
+            _retryCounter --; // decrement retry counter                        
+            resetRX_fifo(); // reset the RX fifo as it has corrupt data            
+          }
+      }      
+    }
+
+    status = _rb.status;
+    if (status == I2C_STATUS_PENDING) return;  // Busy, try next time
+    if (status == I2C_STATUS_OK) {
+     // Send any commands that need to go.
+      processOutgoing(currentMicros);
+     }
+    delayUntil(currentMicros + 10000); // Only enter every 10ms    
+  }
+
+ 
+  // Check for incoming data, and update busy flag and other state accordingly
+ 
+  void processIncoming(unsigned long currentMicros) {
+    // Expected message is in the form "7E FF 06 3D xx xx xx xx xx EF"
+    RX_fifo_lvl();
+    if (FIFO_RX_LEVEL >= 10) {      
+      #ifdef DIAG_I2CDFplayer
+        DIAG(F("I2CDFPlayer: %s Retrieving data from RX Fifo on UART_CH: 0x%x FIFO_RX_LEVEL: %d"),_I2CAddress.toString(), _UART_CH, FIFO_RX_LEVEL); 
+      #endif
+      _outbuffer[0] = REG_RHR << 3 | _UART_CH << 1;
+      // Only copy 10 bytes from RX FIFO, there maybe additional partial return data after a track is finished playing in the RX FIFO
+      I2CManager.read(_I2CAddress, _inbuffer, 10, _outbuffer, 1); // inbuffer[] has the data now
+      //delayUntil(currentMicros + 10000); // Allow time to get the data
+      RX_BUFFER = 10; // We have copied 10 bytes from RX FIFO to _inbuffer
+        #ifdef DIAG_I2CDFplayer_data
+          DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, RX FIFO Data"), _I2CAddress.toString(), _UART_CH);
+          for (int i = 0; i < sizeof _inbuffer; i++){
+            DIAG(F("SC16IS752: Data _inbuffer[0x%x]: 0x%x"), i, _inbuffer[i]);  
+          }
+        #endif       
+    } else {
+        FIFO_RX_LEVEL = 0; //set to 0, we'll read a fresh FIFO_RX_LEVEL next time
+        return; // No data or not enough data in rx fifo, check again next time around
+      }
+
+    
+    bool ok = false;
+    //DIAG(F("I2CDFPlayer: RX_BUFFER: %d"), RX_BUFFER);
+    while (RX_BUFFER != 0) {
+      int c = _inbuffer[_inputIndex]; // Start at 0, increment to FIFO_RX_LEVEL
+      switch (_inputIndex) {
+        case 0:
+          if (c == 0x7E) ok = true;
+          break;
+        case 1:
+          if (c == 0xFF) ok = true;
+          break;
+        case 2:
+          if (c== 0x06) ok = true;
+          break;
+        case 3:
+          _recvCMD = c; // CMD byte
+          ok = true;
+          break;
+        case 6:
+          switch (_recvCMD) {
+            //DIAG(F("I2CDFPlayer: %s, _recvCMD: 0x%x _awaitingResponse: 0x0%x"),_I2CAddress.toString(), _recvCMD, _awaitingResponse);
+            case 0x42:
+              // Response to status query
+              _playing = (c != 0);              
+              // Mark the device online and cancel timeout
+              if (_deviceState==DEVSTATE_INITIALISING) {
+                _deviceState = DEVSTATE_NORMAL;
+                #ifdef DIAG_I2CDFplayer
+                 DIAG(F("I2CDFPlayer: %s, UART_CH: 0x0%x, _deviceState: 0x0%x"),_I2CAddress.toString(), _UART_CH, _deviceState);
+                #endif 
+                #ifdef DIAG_IO
+                _display();
+                #endif
+              }
+              _awaitingResponse = false;
+              break;
+            case 0x3d:            
+              // End of play
+              if (_playing) {
+                #ifdef DIAG_IO
+                  DIAG(F("I2CDFPlayer: Finished"));
+                #endif
+                _playing = false;
+              }
+              break;
+            case 0x40:
+              // Error codes; 1: Module Busy
+              DIAG(F("I2CDFPlayer: Error %d returned from device"), c);
+              _playing = false;
+              break;
+          }
+          ok = true;
+          break;
+        case 4: case 5: case 7: case 8: 
+          ok = true;  // Skip over these bytes in message.
+          break;
+        case 9:
+          if (c==0xef) {
+            // Message finished
+            _retryCounter = RETRYCOUNT; // reset the retry counter as we have received a valid packet
+          }
+          break;
+        default:
+          break;
+      }
+      if (ok){
+        _inputIndex++;  // character as expected, so increment index
+        RX_BUFFER --; // Decrease FIFO_RX_LEVEL with each character read from _inbuffer[_inputIndex]
+      } else {
+        _inputIndex = 0;  // otherwise reset.
+        RX_BUFFER = 0;
+      }
+    }
+    RX_BUFFER = 0; //Set to 0, we'll read a new RX FIFO level again
+  }
+
+
+  // Send any commands that need to be sent
+  void processOutgoing(unsigned long currentMicros) {
+    // When two commands are sent in quick succession, the device will often fail to 
+    // execute one.  Testing has indicated that a delay of 100ms or more is required
+    // between successive commands to get reliable operation.
+    // If 100ms has elapsed since the last thing sent, then check if there's some output to do.
+    if (((int32_t)currentMicros - _commandSendTime) > 100000) {
+      if ( _resetCmd == true){
+          sendPacket(0x0C,0,0);
+          _resetCmd = false;          
+      } else if(_volCmd == true) { // do the volme before palying a track
+         if(_requestedVolumeLevel >= 0 && _requestedVolumeLevel <= 30){         
+         _currentVolume = _requestedVolumeLevel; // If _requestedVolumeLevel is out of range, sent _currentV1olume      
+         }
+         sendPacket(0x06, 0x00, _currentVolume);
+        _volCmd = false;
+      } else if (_playCmd == true) {
+        // Change song
+        if (_requestedSong != -1) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: _requestedVolumeLevel: %u, _requestedSong: %u, _currentFolder: %u _playCmd: 0x%x"), _requestedVolumeLevel, _requestedSong, _currentFolder, _playCmd);
+          #endif               
+          sendPacket(0x0F, _currentFolder, _requestedSong);  // audio file in folder          
+          _requestedSong = -1; 
+          _playCmd = false;
+        }           
+      } //else if (_requestedSong == 0) {
+        else if (_stopplayCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Stop playing: _stopplayCmd: 0x%x"), _stopplayCmd);
+          #endif
+        sendPacket(0x16, 0x00, 0x00);  // Stop playing        
+        _requestedSong = -1;
+        _repeat = false; // reset repeat        
+        _stopplayCmd = false;
+        } else if (_folderCmd == true) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Folder: _folderCmd: 0x%x, _requestedFolder: %d"), _stopplayCmd, _requestedFolder);
+          #endif
+          if (_currentFolder != _requestedFolder){
+            _currentFolder = _requestedFolder;
+          }
+          _folderCmd = false;
+      } else if (_repeatCmd == true) {
+        if(_repeat == false) { // No repeat play currently
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Repeat: _repeatCmd: 0x%x, _requestedSong: %d, _repeat: 0x0%x"), _repeatCmd, _requestedSong, _repeat);
+          #endif 
+          sendPacket(0x08, 0x00, _requestedSong);  // repeat playing audio file in root folder          
+          _requestedSong = -1;
+          _repeat = true; 
+        }
+        _repeatCmd= false;      
+      } else if (_daconCmd == true) { // Always turn DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: DACON: _daconCmd: 0x%x"), _daconCmd);
+        #endif 
+        sendPacket(0x1A,0,0x00);
+        _daconCmd = false;
+      } else if (_eqCmd == true){ // Set Equalizer, values 0x00 - 0x05        
+        if (_currentEQvalue != _requestedEQValue){
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: EQ: _eqCmd: 0x%x, _currentEQvalue: 0x0%x, _requestedEQValue: 0x0%x"), _eqCmd, _currentEQvalue, _requestedEQValue);
+          #endif 
+          _currentEQvalue = _requestedEQValue;
+          sendPacket(0x07,0x00,_currentEQvalue);
+        }
+        _eqCmd = false;
+      } else if (_setamCmd == true){ // Set Audio mixer channel
+         setGPIO(); // Set the audio mixer channel
+         /*        
+          if (_audioMixer == 1){ // set to audio mixer 1       
+            if (_UART_CH == 0){ 
+              TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+            } else { // must be UART 1
+              TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+              }
+           //_setamCmd = false;
+           //UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+          } else { // set to audio mixer 2
+              if (_UART_CH == 0){ 
+                TEMP_REG_VAL &= (0x00 << _UART_CH); //Set GPIO pin 0 to Low
+              } else { // must be UART 1
+                TEMP_REG_VAL &= (0x00 << _UART_CH); //Set GPIO pin 1 to Low
+                }
+              //_setamCmd = false;
+              //UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+            }*/
+        _setamCmd = false;        
+      } else if ((int32_t)currentMicros - _commandSendTime > 1000000) {
+        // Poll device every second that other commands aren't being sent,
+        // to check if it's still connected and responding.
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive") );
+          #endif
+        sendPacket(0x42,0,0); 
+        if (!_awaitingResponse) {
+          #ifdef DIAG_I2CDFplayer_playing
+           DIAG(F("I2CDFPlayer: Send keepalive, _awaitingResponse: 0x0%x"), _awaitingResponse );
+          #endif
+          _timeoutTime = currentMicros + 5000000UL;  // Timeout if no response within 5 seconds
+          _awaitingResponse = true;
+        }
+      }
+    }  
+  }
+
+
+  // Write to a vPin will do nothing
+  void _write(VPIN vpin, int value) override {
+    if (_deviceState == DEVSTATE_FAILED) return;
+      #ifdef DIAG_IO
+        DIAG(F("I2CDFPlayer: Writing to any vPin not supported"));
+      #endif
+  }
+
+
+  // WriteAnalogue on first pin uses the nominated value as a file number to start playing, if file number > 0.
+  // Volume may be specified as second parameter to writeAnalogue.
+  // If value is zero, the player stops playing.  
+  // WriteAnalogue on second pin sets the output volume.
+  //
+  // WriteAnalogue to be done on first vpin
+  //
+  //void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t=0) override { 
+  void _writeAnalogue(VPIN vpin, int value, uint8_t volume=0, uint16_t cmd=0) override { 
+    if (_deviceState == DEVSTATE_FAILED) return;    
+    #ifdef DIAG_IO
+      DIAG(F("I2CDFPlayer: VPIN:%u FileNo:%d Volume:%d Command:0x%x"), vpin, value, volume, cmd);
+    #endif
+    uint8_t pin = vpin - _firstVpin;
+    if (pin == 0) { // Enhanced DFPlayer commands, do nothing if not vPin 0     
+     // Read command and value
+      switch (cmd){
+       //case NONE:
+       // DFPlayerCmd = cmd;
+       // break;
+       case PLAY:
+        _playCmd = true;
+        _volCmd = true;        
+        _requestedSong = value;
+        _requestedVolumeLevel = volume; 
+        _playing = true;        
+        break;
+        case VOL:
+          _volCmd = true;          
+          _requestedVolumeLevel = volume;
+        break;
+       case FOLDER:
+        _folderCmd = true;
+        if (volume <= 0 || volume > 99){ // Range checking, valid values 1-99, else default to 1
+          _requestedFolder = 0x01; // if outside range, default to folder 01  
+        } else {
+          _requestedFolder = volume;
+        }        
+        break;
+       case REPEATPLAY: // Need to check if _repeat == true, if so do nothing        
+        if (_repeat == false) {
+           #ifdef DIAG_I2CDFplayer_playing
+              DIAG(F("I2CDFPlayer: WriteAnalog Repeat: _repeat: 0x0%x, value: %d _repeatCmd: 0x%x"), _repeat, value, _repeatCmd);
+           #endif
+          _repeatCmd = true;          
+          _requestedSong = value;
+          _requestedVolumeLevel = volume;
+          _playing = true;         
+        }
+        break;
+       case STOPPLAY:
+        _stopplayCmd = true;        
+        break;
+       case EQ:
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WriteAnalog EQ: cmd: 0x%x, EQ value: 0x%x"), cmd, volume);
+        #endif
+        _eqCmd = true;        
+        if (volume <= 0 || volume > 5) { // If out of range, default to NORMAL
+          _requestedEQValue = NORMAL;            
+        } else { // Valid EQ parameter range
+          _requestedEQValue = volume;     
+          }
+        break;        
+       case RESET:
+        _resetCmd = true;      
+        break; 
+       case DACON: // Works, but without the DACOFF command limited value, except when not relying on DFPlayer default to turn the DAC on
+        #ifdef DIAG_I2CDFplayer_playing
+          DIAG(F("I2CDFPlayer: WrtieAnalog DACON: cmd: 0x%x"), cmd);
+        #endif
+        _daconCmd = true;
+        break;
+        case SETAM: // Set the audio mixer channel to 1 or 2
+          _setamCmd = true;
+          #ifdef DIAG_I2CDFplayer_playing
+            DIAG(F("I2CDFPlayer: WrtieAnalog SETAM: cmd: 0x%x"), cmd);
+          #endif
+          if (volume <= 0 || volume > 2) { // If out of range, default to 1
+            _audioMixer = 1;            
+          } else { // Valid SETAM parameter in range
+              _audioMixer = volume; // _audioMixer valid values 1 or 2
+            }          
+        break;
+       default:
+        break;
+      }
+    }    
+  }
+
+  // A read on any pin indicates if the player is still playing.
+  int _read(VPIN vpin) override {
+    if (_deviceState == DEVSTATE_FAILED) return false;
+    uint8_t pin = vpin - _firstVpin;
+      if (pin == 0) { // Do nothing if not vPin 0
+        return _playing;
+      }
+    }
+
+  void _display() override {
+    DIAG(F("I2CDFPlayer Configured on Vpins:%u-%u %S"), _firstVpin, _firstVpin+_nPins-1,
+      (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
+  }
+  
+private: 
+  // DFPlayer command frame
+  // 7E FF 06 0F 00 01 01 xx xx EF
+  // 0	  ->	7E is start code
+  // 1	  ->	FF is version
+  // 2	  ->	06 is length
+  // 3	  ->	0F is command
+  // 4	  ->	00 is no receive
+  // 5~6	->	01 01 is argument
+  // 7~8	->	checksum = 0 - ( FF+06+0F+00+01+01 )
+  // 9	  ->	EF is end code
+
+  void sendPacket(uint8_t command, uint8_t arg1 = 0, uint8_t arg2 = 0) {
+    FIFO_TX_LEVEL = 0; // Reset FIFO_TX_LEVEL    
+    uint8_t out[] = {
+        0x7E,
+        0xFF,
+        06,
+        command,
+        00,
+        //static_cast<uint8_t>(arg >> 8),
+        //static_cast<uint8_t>(arg & 0x00ff),
+        arg1,
+        arg2,
+        00,
+        00,
+        0xEF };
+
+    setChecksum(out);
+
+      // Prepend the DFPlayer command with REG address and UART Channel in _outbuffer
+      _outbuffer[0] = REG_THR << 3 | _UART_CH << 1; //TX FIFO and UART Channel      
+      for ( int i = 1; i < sizeof(out)+1 ; i++){
+        _outbuffer[i] = out[i-1];
+      }
+
+      #ifdef DIAG_I2CDFplayer_data
+       DIAG(F("SC16IS752: I2C: %s Sent packet function"), _I2CAddress.toString());
+       for (int i = 0; i < sizeof _outbuffer; i++){
+        DIAG(F("SC16IS752: Data _outbuffer[0x%x]: 0x%x"), i, _outbuffer[i]);  
+       }
+      #endif
+      
+    TX_fifo_lvl();
+    if(FIFO_TX_LEVEL > 0){ //FIFO is empty
+      I2CManager.write(_I2CAddress, _outbuffer, sizeof(_outbuffer), &_rb);
+      //I2CManager.write(_I2CAddress, _outbuffer, sizeof(_outbuffer));
+      #ifdef DIAG_I2CDFplayer
+       DIAG(F("SC16IS752: I2C: %s data transmit complete on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+      #endif
+    } else {
+      DIAG(F("I2CDFPlayer at: %s, TX FIFO not empty on UART: 0x%x"), _I2CAddress.toString(), _UART_CH);
+      _deviceState = DEVSTATE_FAILED; // This should not happen      
+    }
+    _commandSendTime = micros();
+  }
+
+  uint16_t calcChecksum(uint8_t* packet)
+  {
+    uint16_t sum = 0;
+    for (int i = 1; i < 7; i++)
+    {
+      sum += packet[i];
+    }
+    return -sum;
+  }
+
+  void setChecksum(uint8_t* out)
+  {
+    uint16_t sum = calcChecksum(out);
+    out[7] = (sum >> 8);
+    out[8] = (sum & 0xff);
+  }
+
+  // SC16IS752 functions
+  // Initialise SC16IS752 only for this channel
+  // First a software reset
+  // Enable FIFO and clear TX & RX FIFO
+  // Need to set the following registers
+  // IOCONTROL set bit 1 and 2 to 0 indicating that they are GPIO
+  // IODIR set all bit to 1 indicating al are output
+  // IOSTATE set only bit 0 to 1 for UART 0, or only bit 1 for UART 1  // 
+  // LCR bit 7=0 divisor latch (clock division registers DLH & DLL, they store 16 bit divisor), 
+  //     WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE
+  // MCR bit 7=0 clock divisor devide-by-1 clock input
+  // DLH most significant part of divisor
+  // DLL least significant part of divisor
+  //
+  // BAUD_RATE, WORD_LEN, STOP_BIT, PARITY_ENA and PARITY_TYPE have been defined and initialized
+  // 
+  void Init_SC16IS752(){ // Return value is in _deviceState
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: Initialize I2C: %s , UART Ch: 0x%x"), _I2CAddress.toString(),  _UART_CH);      
+    #endif
+    uint16_t _divisor = (SC16IS752_XTAL_FREQ / PRESCALER) / (BAUD_RATE * 16);
+    TEMP_REG_VAL = 0x08; // UART Software reset
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set pins to GPIO mode
+    UART_WriteRegister(REG_IOCONTROL, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0xFF; //Set all pins as output
+    UART_WriteRegister(REG_IODIR, TEMP_REG_VAL);
+    UART_ReadRegister(REG_IOSTATE); // Read current state as not to overwrite the other GPIO pins
+    TEMP_REG_VAL = _inbuffer[0];
+    setGPIO(); // Set the audio mixer channel
+    /*
+    if (_UART_CH == 0){ // Set Audio mixer channel
+      TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+    } else { // must be UART 1
+      TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+    }
+    UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+    */
+    TEMP_REG_VAL = 0x07; // Reset FIFO, clear RX & TX FIFO
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x00; // Set MCR to all 0, includes Clock divisor
+    UART_WriteRegister(REG_MCR, TEMP_REG_VAL);
+    TEMP_REG_VAL = 0x80 | WORD_LEN | STOP_BIT | PARITY_ENA | PARITY_TYPE;
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch enabled
+    UART_WriteRegister(REG_DLL, (uint8_t)_divisor);  // Write DLL
+    UART_WriteRegister(REG_DLH, (uint8_t)(_divisor >> 8)); // Write DLH
+    UART_ReadRegister(REG_LCR);
+    TEMP_REG_VAL = _inbuffer[0] & 0x7F; // Disable Divisor latch enabled bit
+    UART_WriteRegister(REG_LCR, TEMP_REG_VAL); // Divisor latch disabled  
+
+    uint8_t status = _rb.status;
+    if (status != I2C_STATUS_OK) {
+      DIAG(F("SC16IS752: I2C: %s failed %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      _deviceState = DEVSTATE_FAILED;
+    } else {
+      #ifdef DIAG_IO
+       DIAG(F("SC16IS752: I2C: %s, _deviceState: %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
+      #endif
+     _deviceState = DEVSTATE_NORMAL; // If I2C state is OK, then proceed to initialize DFPlayer 
+    }
+  }
+
+  
+  // Read the Receive FIFO Level register (RXLVL), return a single unsigned integer
+  // of nr of characters in the RX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40) Only display if RX FIFO has data
+  // The RX fifo level is used to check if there are enough bytes to process a frame
+  void RX_fifo_lvl(){
+    UART_ReadRegister(REG_RXLV);
+    FIFO_RX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+     if (FIFO_RX_LEVEL > 0){
+     //if (FIFO_RX_LEVEL > 0 && FIFO_RX_LEVEL < 10){
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_RX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, _inbuffer[0]);
+    }
+    #endif   
+  }
+
+  // When a frame is transmitted from the DFPlayer to the serial port, and at the same time the CS is sending a 42 query
+  // the following two frames from the DFPlayer are corrupt. This result in the receive buffer being out of sync and the 
+  // CS will complain and generate a timeout.
+  // The RX fifo has corrupt data and need to be flushed, this function does that
+  // 
+  void resetRX_fifo(){
+    #ifdef DIAG_I2CDFplayer
+      DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, RX fifo reset"), _I2CAddress.toString(), _UART_CH);
+    #endif    
+    TEMP_REG_VAL = 0x03; // Reset RX fifo
+    UART_WriteRegister(REG_FCR, TEMP_REG_VAL);
+  }
+
+  // Set or reset GPIO pin 0 and 1 depending on the UART ch
+  // This function may be modified in a future release to enable all 8 pins to be set or reset with EX-Rail
+  // for various auxilary functions
+  void setGPIO(){
+    UART_ReadRegister(REG_IOSTATE); // Get the current GPIO pins state from the IOSTATE register
+    TEMP_REG_VAL = _inbuffer[0];
+    if (_audioMixer == 1){ // set to audio mixer 1
+      if (_UART_CH == 0){ 
+        TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 0 to high
+      } else { // must be UART 1
+         TEMP_REG_VAL |= (0x01 << _UART_CH); //Set GPIO pin 1 to high
+        }
+    } else { // set to audio mixer 2
+        if (_UART_CH == 0){ 
+          TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 0 to Low
+        } else { // must be UART 1
+           TEMP_REG_VAL &= ~(0x01 << _UART_CH); //Set GPIO pin 1 to Low
+          }
+      }    
+    UART_WriteRegister(REG_IOSTATE, TEMP_REG_VAL);
+    _setamCmd = false;  
+  }
+  
+
+  // Read the Tranmit FIFO Level register (TXLVL), return a single unsigned integer
+  // of nr characters free in the TX FIFO, bit 6:0, 7 not used, set to zero
+  // value from 0 (0x00) to 64 (0x40)
+  //
+  void TX_fifo_lvl(){
+    UART_ReadRegister(REG_TXLV);
+    FIFO_TX_LEVEL = _inbuffer[0];
+    #ifdef DIAG_I2CDFplayer
+    //  DIAG(F("SC16IS752: At I2C: %s, UART channel: 0x%x, FIFO_TX_LEVEL: 0d%d"), _I2CAddress.toString(), _UART_CH, FIFO_TX_LEVEL);
+    #endif 
+  }
+
+
+  //void UART_WriteRegister(I2CAddress _I2CAddress, uint8_t _UART_CH, uint8_t UART_REG, uint8_t Val, I2CRB &_rb){
+  void UART_WriteRegister(uint8_t UART_REG, uint8_t Val){
+    _outbuffer[0] = UART_REG << 3 | _UART_CH << 1;
+    _outbuffer[1] = Val;
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Write register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _outbuffer[1]);
+    #endif
+    I2CManager.write(_I2CAddress, _outbuffer, 2);
+  }
+
+ 
+  void UART_ReadRegister(uint8_t UART_REG){
+     _outbuffer[0] = UART_REG << 3 | _UART_CH << 1; // _outbuffer[0] has now UART_REG and UART_CH
+     I2CManager.read(_I2CAddress, _inbuffer, 1, _outbuffer, 1);    
+    // _inbuffer has the REG data
+    #ifdef DIAG_I2CDFplayer_reg
+      DIAG(F("SC16IS752: Read register at I2C: %s, UART channel: 0x%x, Register: 0x%x, Data: 0b%b"), _I2CAddress.toString(), _UART_CH, UART_REG, _inbuffer[0]);
+    #endif
+  }
+
+// SC16IS752 General register set (from the datasheet)
+enum : uint8_t{
+    REG_RHR       = 0x00, // FIFO Read
+    REG_THR       = 0x00, // FIFO Write
+    REG_IER       = 0x01, // Interrupt Enable Register R/W
+    REG_FCR       = 0x02, // FIFO Control Register Write
+    REG_IIR       = 0x02, // Interrupt Identification Register Read
+    REG_LCR       = 0x03, // Line Control Register R/W
+    REG_MCR       = 0x04, // Modem Control Register R/W
+    REG_LSR       = 0x05, // Line Status Register Read
+    REG_MSR       = 0x06, // Modem Status Register Read
+    REG_SPR       = 0x07, // Scratchpad Register R/W
+    REG_TCR       = 0x06, // Transmission Control Register R/W
+    REG_TLR       = 0x07, // Trigger Level Register R/W    
+    REG_TXLV      = 0x08, // Transmitter FIFO Level register Read
+    REG_RXLV      = 0x09, // Receiver FIFO Level register Read
+    REG_IODIR     = 0x0A, // Programmable I/O pins Direction register R/W
+    REG_IOSTATE   = 0x0B, // Programmable I/O pins State register R/W
+    REG_IOINTENA  = 0x0C, // I/O Interrupt Enable register R/W
+    REG_IOCONTROL = 0x0E, // I/O Control register R/W
+    REG_EFCR      = 0x0F, // Extra Features Control Register R/W
+  };
+
+// SC16IS752 Special register set
+enum : uint8_t{
+    REG_DLL       = 0x00, // Division registers R/W
+    REG_DLH       = 0x01, // Division registers R/W
+  };
+
+// SC16IS752 Enhanced regiter set
+enum : uint8_t{
+    REG_EFR       = 0X02, // Enhanced Features Register R/W
+    REG_XON1      = 0x04, // R/W
+    REG_XON2      = 0x05, // R/W
+    REG_XOFF1     = 0x06, // R/W
+    REG_XOFF2     = 0x07, // R/W
+  };
+
+// DFPlayer commands and values
+enum  : uint8_t{
+    PLAY          = 0x0F,
+    VOL           = 0x06,
+    FOLDER        = 0x2B, // Not a DFPlayer command, used to set folder nr where audio file is
+    REPEATPLAY    = 0x08,
+    STOPPLAY      = 0x16,
+    EQ            = 0x07, // Set equaliser, require parameter NORMAL, POP, ROCK, JAZZ, CLASSIC or BASS
+    RESET         = 0x0C,
+    DACON         = 0x1A,
+    SETAM         = 0x2A, // Set audio mixer 1 or 2 for this DFPLayer   
+    NORMAL        = 0x00, // Equalizer parameters
+    POP           = 0x01,
+    ROCK          = 0x02,
+    JAZZ          = 0x03,
+    CLASSIC       = 0x04,
+    BASS          = 0x05,    
+  };
+
+};
+
+#endif // IO_I2CDFPlayer_h

IO_PCA9555.h

@@ -33,17 +33,16 @@ public:
   static void create(VPIN vpin, uint8_t nPins, I2CAddress i2cAddress, int interruptPin=-1) {
     if (checkNoOverlap(vpin, nPins, i2cAddress)) new PCA9555(vpin,nPins, i2cAddress, interruptPin);
   }
-  
+
+private:  
   // Constructor
-  PCA9555(VPIN vpin, int nPins, uint8_t I2CAddress, int interruptPin=-1) 
+  PCA9555(VPIN vpin, uint8_t nPins, I2CAddress I2CAddress, int interruptPin=-1) 
     : GPIOBase<uint16_t>((FSH *)F("PCA9555"), vpin, nPins, I2CAddress, interruptPin) 
   {
     requestBlock.setRequestParams(_I2CAddress, inputBuffer, sizeof(inputBuffer),
       outputBuffer, sizeof(outputBuffer));
     outputBuffer[0] = REG_INPUT_P0;
   }
-
-private:
   void _writeGpioPort() override {
     I2CManager.write(_I2CAddress, 3, REG_OUTPUT_P0, _portOutputState, _portOutputState>>8);
   }

IO_Template.h

@@ -0,0 +1,69 @@
+
+/*
+* Creation - a create() function and constructor are required;
+* Initialisation - a _begin() function is written (optional);
+* Background operations - a _loop() function is written (optional);
+* Operations - you can optionally supply any of _write() (digital) function, _writeAnalogue() function, _read() (digital) function and _readAnalogue() function.
+*
+*
+*
+*
+*
+*
+*/
+
+
+#ifndef IO_MYDEVICE_H
+#define IO_MYDEVICE_H
+
+#include "IODevice.h"
+#include "DIAG.h"  // for DIAG calls
+
+class MyDevice: public IODevice {
+public:
+  // Constructor
+  MyDevice(VPIN firstVpin, int nPins) {
+    _firstVpin = firstVpin;
+    _nPins = min(nPins,16);
+    // Other object initialisation here
+    // ...
+    addDevice(this);
+  }
+  static void create(VPIN firstVpin, int nPins, uint8_t i2cAddress) {
+    new MyDevice(firstVpin, nPins);
+  }
+private:
+  void _begin() override {
+    // Initialise device
+    // ...
+  }
+  void _loop(unsigned long currentMicros) override {
+    // Regular operations, e.g. acquire data
+    // ...
+    delayUntil(currentMicros + 10*1000UL);  // 10ms till next entry
+  }
+  int _readAnalogue(VPIN vpin) override {
+    // Return acquired data value, e.g.
+    int pin = vpin - _firstVpin;
+    return _value[pin];
+  }
+  int _read(VPIN vpin) override {
+    // Return acquired data value, e.g.
+    int pin = vpin - _firstVpin;
+    return _value[pin];
+  }
+  void write(VPIN vpin, int value) override {
+    // Do something with value , e.g. write to device.
+    // ...
+  }
+  void writeAnalogue(VPIN vpin, int value) override {
+    // Do something with value, e.g. write to device.
+    // ...
+  }
+  void _display() override {
+    DIAG(F("MyDevice Configured on Vpins:%d-%d %S"), _firstVpin, _firstVpin+_nPins-1,
+      _deviceState == DEVSTATE_FAILED ? F("OFFLINE") : F(""));
+  }
+  uint16_t _value[16];
+};
+#endif // IO_MYDEVICE_H

MotorDriver.cpp

@@ -34,6 +34,11 @@ unsigned long MotorDriver::globalOverloadStart = 0;
 volatile portreg_t shadowPORTA;
 volatile portreg_t shadowPORTB;
 volatile portreg_t shadowPORTC;
+#if defined(ARDUINO_ARCH_STM32)
+volatile portreg_t shadowPORTD;
+volatile portreg_t shadowPORTE;
+volatile portreg_t shadowPORTF;
+#endif
 
 MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, int16_t brake_pin,
                          byte current_pin, float sense_factor, unsigned int trip_milliamps, int16_t fault_pin) {
@@ -68,6 +73,21 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
     fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &shadowPORTC;
   }
+  if (HAVE_PORTD(fastSignalPin.inout == &PORTD)) {
+    DIAG(F("Found PORTD pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
+    fastSignalPin.inout = &shadowPORTD;
+  }
+  if (HAVE_PORTE(fastSignalPin.inout == &PORTE)) {
+    DIAG(F("Found PORTE pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
+    fastSignalPin.inout = &shadowPORTE;
+  }
+  if (HAVE_PORTF(fastSignalPin.inout == &PORTF)) {
+    DIAG(F("Found PORTF pin %d"),signalPin);
+    fastSignalPin.shadowinout = fastSignalPin.inout;
+    fastSignalPin.inout = &shadowPORTF;
+  }
 
   signalPin2=signal_pin2;
   if (signalPin2!=UNUSED_PIN) {
@@ -91,6 +111,21 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
       fastSignalPin2.shadowinout = fastSignalPin2.inout;
       fastSignalPin2.inout = &shadowPORTC;
     }
+    if (HAVE_PORTD(fastSignalPin2.inout == &PORTD)) {
+      DIAG(F("Found PORTD pin %d"),signalPin2);
+      fastSignalPin2.shadowinout = fastSignalPin2.inout;
+      fastSignalPin2.inout = &shadowPORTD;
+    }
+    if (HAVE_PORTE(fastSignalPin2.inout == &PORTE)) {
+      DIAG(F("Found PORTE pin %d"),signalPin2);
+      fastSignalPin2.shadowinout = fastSignalPin2.inout;
+      fastSignalPin2.inout = &shadowPORTE;
+    }
+    if (HAVE_PORTF(fastSignalPin2.inout == &PORTF)) {
+      DIAG(F("Found PORTF pin %d"),signalPin2);
+      fastSignalPin2.shadowinout = fastSignalPin2.inout;
+      fastSignalPin2.inout = &shadowPORTF;
+    }
   }
   else dualSignal=false; 
   
@@ -279,7 +314,7 @@ void MotorDriver::startCurrentFromHW() {
 #pragma GCC pop_options
 #endif //ANALOG_READ_INTERRUPT
 
-#if defined(ARDUINO_ARCH_ESP32)
+#if defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_STM32)
 #ifdef VARIABLE_TONES
 uint16_t taurustones[28] = { 165, 175, 196, 220,
 			     247, 262, 294, 330,
@@ -330,7 +365,7 @@ void MotorDriver::setDCSignal(byte speedcode) {
   byte tSpeed=speedcode & 0x7F; // DCC Speed with 0,1 stop and speed steps 2 to 127
   byte tDir=speedcode & 0x80;
   byte brake;
-#if defined(ARDUINO_ARCH_ESP32)
+#if defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_STM32)
   {
     int f = 131;
 #ifdef VARIABLE_TONES
@@ -348,7 +383,7 @@ void MotorDriver::setDCSignal(byte speedcode) {
   else  brake = 2 * (128-tSpeed);
   if (invertBrake)
     brake=255-brake;
-#if defined(ARDUINO_ARCH_ESP32)
+#if defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_STM32)
   DCCTimer::DCCEXanalogWrite(brakePin,brake);
 #else
   analogWrite(brakePin,brake);
@@ -372,6 +407,24 @@ void MotorDriver::setDCSignal(byte speedcode) {
     setSignal(tDir);
     HAVE_PORTC(PORTC=shadowPORTC);
     interrupts();
+  } else if (HAVE_PORTD(fastSignalPin.shadowinout == &PORTD)) {
+    noInterrupts();
+    HAVE_PORTD(shadowPORTD=PORTD);
+    setSignal(tDir);
+    HAVE_PORTD(PORTD=shadowPORTD);
+    interrupts();
+  } else if (HAVE_PORTE(fastSignalPin.shadowinout == &PORTE)) {
+    noInterrupts();
+    HAVE_PORTE(shadowPORTE=PORTE);
+    setSignal(tDir);
+    HAVE_PORTE(PORTE=shadowPORTE);
+    interrupts();
+  } else if (HAVE_PORTF(fastSignalPin.shadowinout == &PORTF)) {
+    noInterrupts();
+    HAVE_PORTF(shadowPORTF=PORTF);
+    setSignal(tDir);
+    HAVE_PORTF(PORTF=shadowPORTF);
+    interrupts();
   } else {
     noInterrupts();
     setSignal(tDir);
@@ -393,6 +446,13 @@ void MotorDriver::throttleInrush(bool on) {
   } else {
     ledcDetachPin(brakePin);
   }
+#elif defined(ARDUINO_ARCH_STM32)
+  if(on) {
+    DCCTimer::DCCEXanalogWriteFrequency(brakePin, 62500);
+    DCCTimer::DCCEXanalogWrite(brakePin,duty);
+  } else {
+    pinMode(brakePin, OUTPUT);
+  }
 #else
   if(on){
     switch(brakePin) {

MotorDriver.h

@@ -1,5 +1,5 @@
 /*
- *  © 2022 Paul M Antoine
+ *  © 2022-2023 Paul M. Antoine
  *  © 2021 Mike S
  *  © 2021 Fred Decker
  *  © 2020 Chris Harlow
@@ -60,6 +60,16 @@ enum TRACK_MODE : byte {TRACK_MODE_NONE = 1, TRACK_MODE_MAIN = 2, TRACK_MODE_PRO
 #define HAVE_PORTB(X) X
 #define PORTC GPIOC->ODR
 #define HAVE_PORTC(X) X
+#define PORTD GPIOD->ODR
+#define HAVE_PORTD(X) X
+#if defined(GPIOE)
+#define PORTE GPIOE->ODR
+#define HAVE_PORTE(X) X
+#endif
+#if defined(GPIOF)
+#define PORTF GPIOF->ODR
+#define HAVE_PORTF(X) X
+#endif
 #endif
 
 // if macros not defined as pass-through we define
@@ -74,6 +84,15 @@ enum TRACK_MODE : byte {TRACK_MODE_NONE = 1, TRACK_MODE_MAIN = 2, TRACK_MODE_PRO
 #ifndef HAVE_PORTC
 #define HAVE_PORTC(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
 #endif
+#ifndef HAVE_PORTD
+#define HAVE_PORTD(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
+#endif
+#ifndef HAVE_PORTE
+#define HAVE_PORTE(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
+#endif
+#ifndef HAVE_PORTF
+#define HAVE_PORTF(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
+#endif
 
 // Virtualised Motor shield 1-track hardware Interface
 
@@ -110,6 +129,9 @@ struct FASTPIN {
 extern volatile portreg_t shadowPORTA;
 extern volatile portreg_t shadowPORTB;
 extern volatile portreg_t shadowPORTC;
+extern volatile portreg_t shadowPORTD;
+extern volatile portreg_t shadowPORTE;
+extern volatile portreg_t shadowPORTF;
 
 enum class POWERMODE : byte { OFF, ON, OVERLOAD, ALERT };
 
@@ -163,16 +185,16 @@ class MotorDriver {
     unsigned int raw2mA( int raw);
     unsigned int mA2raw( unsigned int mA);
     inline bool brakeCanPWM() {
-#if defined(ARDUINO_ARCH_ESP32) || defined(__arm__)
-      // TODO: on ARM we can use digitalPinHasPWM, and may wish/need to
-      return true;
-#else
-#ifdef digitalPinToTimer
+#if defined(ARDUINO_ARCH_ESP32)
+      return (brakePin != UNUSED_PIN); // This was just (true) but we probably do need to check for UNUSED_PIN!
+#elif defined(__arm__)
+      // On ARM we can use digitalPinHasPWM
+      return ((brakePin!=UNUSED_PIN) && (digitalPinHasPWM(brakePin)));
+#elif defined(digitalPinToTimer)
       return ((brakePin!=UNUSED_PIN) && (digitalPinToTimer(brakePin)));
 #else
       return (brakePin<14 && brakePin >1);
-#endif //digitalPinToTimer
-#endif //ESP32/ARM
+#endif
     }
     inline int getRawCurrentTripValue() {
 	    return rawCurrentTripValue;

TrackManager.cpp

@@ -154,10 +154,16 @@ void TrackManager::setDCCSignal( bool on) {
   HAVE_PORTA(shadowPORTA=PORTA);
   HAVE_PORTB(shadowPORTB=PORTB);
   HAVE_PORTC(shadowPORTC=PORTC);
+  HAVE_PORTD(shadowPORTD=PORTD);
+  HAVE_PORTE(shadowPORTE=PORTE);
+  HAVE_PORTF(shadowPORTF=PORTF);
   APPLY_BY_MODE(TRACK_MODE_MAIN,setSignal(on));
   HAVE_PORTA(PORTA=shadowPORTA);
   HAVE_PORTB(PORTB=shadowPORTB);
   HAVE_PORTC(PORTC=shadowPORTC);
+  HAVE_PORTD(PORTD=shadowPORTD);
+  HAVE_PORTE(PORTE=shadowPORTE);
+  HAVE_PORTF(PORTF=shadowPORTF);
 }
 
 void TrackManager::setCutout( bool on) {
@@ -172,10 +178,16 @@ void TrackManager::setPROGSignal( bool on) {
   HAVE_PORTA(shadowPORTA=PORTA);
   HAVE_PORTB(shadowPORTB=PORTB);
   HAVE_PORTC(shadowPORTC=PORTC);
+  HAVE_PORTD(shadowPORTD=PORTD);
+  HAVE_PORTE(shadowPORTE=PORTE);
+  HAVE_PORTF(shadowPORTF=PORTF);
   APPLY_BY_MODE(TRACK_MODE_PROG,setSignal(on));
   HAVE_PORTA(PORTA=shadowPORTA);
   HAVE_PORTB(PORTB=shadowPORTB);
   HAVE_PORTC(PORTC=shadowPORTC);
+  HAVE_PORTD(PORTD=shadowPORTD);
+  HAVE_PORTE(PORTE=shadowPORTE);
+  HAVE_PORTF(PORTF=shadowPORTF);
 }
 
 // setDCSignal(), called from normal context

defines.h

@@ -144,9 +144,9 @@
     #define DISABLE_EEPROM
   #endif
   // STM32 support for native I2C is awaiting development 
-  #ifndef I2C_USE_WIRE
-  #define I2C_USE_WIRE
-  #endif
+  // #ifndef I2C_USE_WIRE
+  // #define I2C_USE_WIRE
+  // #endif
 
 /* TODO when ready 
 #elif defined(ARDUINO_ARCH_RP2040)

myHal.cpp_example.txt

@@ -24,6 +24,7 @@
 //#include "IO_TouchKeypad.h  // Touch keypad with 16 keys
 //#include "IO_EXTurntable.h"   // Turntable-EX turntable controller
 //#include "IO_EXFastClock.h"  // FastClock driver
+//#include "IO_PCA9555.h"     // 16-bit I/O expander (NXP & Texas Instruments).
 
 //==========================================================================
 // The function halSetup() is invoked from CS if it exists within the build.
@@ -233,6 +234,23 @@ void halSetup() {
   // DFPlayer::create(10000, 10, Serial1);
 
 
+  //=======================================================================
+  // Play mp3 files from a Micro-SD card, using a DFPlayer MP3 Module on a SC16IS752 I2C Dual UART
+  //=======================================================================
+  // DFPlayer via NXP SC16IS752 I2C Dual UART. Each device has 2 UARTs on a single I2C address
+  // Total nr of devices on an I2C bus is 16, with 2 UARTs on each address making a total of 32 UARTs per I2C bus
+  // I2C address range 0x48 - 0x57
+  // I2CDFPlayer::create(1st vPin,vPins, I2C address, UART ch);
+
+  // I2CDFPlayer::create(10000, 10, 0x48, 0);
+  // I2CDFPlayer::create(10010, 10, 0x48, 1);
+
+  // Multiplexer example
+  // I2CDFPlayer::create(10020, 10, {I2CMux_0, SubBus_0, 0x50}, 0);
+
+
+
+
   //=======================================================================
   // 16-pad capacitative touch key pad based on TP229 IC.
   //=======================================================================

platformio.ini

@@ -31,7 +31,6 @@ include_dir = .
 [env]
 build_flags = -Wall -Wextra
 ; monitor_filters = time
-; lib_deps = adafruit/Adafruit ST7735 and ST7789 Library @ ^1.10.0
 
 [env:samd21-dev-usb]
 platform = atmelsam
@@ -60,7 +59,7 @@ framework = arduino
 lib_deps = ${env.lib_deps}
 monitor_speed = 115200
 monitor_echo = yes
-build_flags = -std=c++17 ; -DI2C_USE_WIRE  -DDIAG_LOOPTIMES -DDIAG_IO
+build_flags = -std=c++17
 
 [env:mega2560-debug]
 platform = atmelavr
@@ -72,7 +71,7 @@ lib_deps =
 	SPI
 monitor_speed = 115200
 monitor_echo = yes
-build_flags =  -DDIAG_IO=2 -DDIAG_LOOPTIMES
+build_flags = -DDIAG_IO=2 -DDIAG_LOOPTIMES
 
 [env:mega2560-no-HAL]
 platform = atmelavr
@@ -84,7 +83,7 @@ lib_deps =
 	SPI
 monitor_speed = 115200
 monitor_echo = yes
-build_flags = -DIO_NO_HAL 
+build_flags = -DIO_NO_HAL
 
 [env:mega2560-I2C-wire]
 platform = atmelavr
@@ -108,7 +107,7 @@ lib_deps =
 	SPI
 monitor_speed = 115200
 monitor_echo = yes
-build_flags =     ; -DDIAG_LOOPTIMES
+build_flags = 
 
 [env:mega328]
 platform = atmelavr
@@ -190,10 +189,75 @@ platform = ststm32
 board = nucleo_f446re
 framework = arduino
 lib_deps = ${env.lib_deps}
-build_flags = -std=c++17  -Os -g2 -Wunused-variable ; -DDIAG_LOOPTIMES ; -DDIAG_IO 
+build_flags = -std=c++17  -Os -g2 -Wunused-variable
 monitor_speed = 115200
 monitor_echo = yes
 
+; Experimental - no reason this should not work, but not
+; tested as yet
+;
+[env:Nucleo-F401RE]
+platform = ststm32
+board = nucleo_f401re
+framework = arduino
+lib_deps = ${env.lib_deps}
+build_flags = -std=c++17  -Os -g2 -Wunused-variable
+monitor_speed = 115200
+monitor_echo = yes
+
+; Commented out by default as the F13ZH has variant files
+; but NOT the nucleo_f413zh.json file which needs to be
+; installed before you can let PlatformIO see this
+;
+; [env:Nucleo-F413ZH]
+; platform = ststm32
+; board = nucleo_f413zh
+; framework = arduino
+; lib_deps = ${env.lib_deps}
+; build_flags = -std=c++17  -Os -g2 -Wunused-variable
+; monitor_speed = 115200
+; monitor_echo = yes
+
+; Commented out by default as the F446ZE needs variant files
+; installed before you can let PlatformIO see this
+;
+; [env:Nucleo-F446ZE]
+; platform = ststm32
+; board = nucleo_f446ze
+; framework = arduino
+; lib_deps = ${env.lib_deps}
+; build_flags = -std=c++17  -Os -g2 -Wunused-variable
+; monitor_speed = 115200
+; monitor_echo = yes
+
+; Commented out by default as the F412ZG needs variant files
+; installed before you can let PlatformIO see this
+;
+; [env:Nucleo-F412ZG]
+; platform = ststm32
+; board = blah_f412zg
+; framework = arduino
+; lib_deps = ${env.lib_deps}
+; build_flags = -std=c++17 -Os -g2 -Wunused-variable
+; monitor_speed = 115200
+; monitor_echo = yes
+; upload_protocol = stlink
+
+; Experimental - Ethernet work still in progress
+;
+; [env:Nucleo-F429ZI]
+; platform = ststm32
+; board = nucleo_f429zi
+; framework = arduino
+; lib_deps = ${env.lib_deps}
+; 			arduino-libraries/Ethernet @ ^2.0.1
+; 			stm32duino/STM32Ethernet @ ^1.3.0
+; 			stm32duino/STM32duino LwIP @ ^2.1.2
+; build_flags = -std=c++17 -Os -g2 -Wunused-variable
+; monitor_speed = 115200
+; monitor_echo = yes
+; upload_protocol = stlink
+
 [env:Teensy3_2]
 platform = teensy
 board = teensy31
@@ -232,5 +296,4 @@ board = teensy41
 framework = arduino
 build_flags = -std=c++17  -Os -g2
 lib_deps = ${env.lib_deps}
-lib_ignore = 
-
+lib_ignore =

version.h

@@ -3,7 +3,17 @@
 
 #include "StringFormatter.h"
 
-#define VERSION "5.1.5"
+#define VERSION "5.1.11"
+// 5.1.11 - STM32F4xx revised I2C clock setup, no correctly sets clock and has fully variable frequency selection
+// 5.1.10 - STM32F4xx DCCEXanalogWrite to handle PWM generation for TrackManager DC/DCX
+//        - STM32F4xx DCC 58uS timer now using non-PWM output timers where possible
+//        - ESP32 brakeCanPWM check now detects UNUSED_PIN
+//        - ARM architecture brakeCanPWM now uses digitalPinHasPWM()
+//        - STM32F4xx shadowpin extensions to handle pins on ports D, E and F
+// 5.1.9  - Fixed IO_PCA9555'h to work with PCA9548 mux, tested OK
+// 5.1.8  - STM32Fxx ADCee extension to support ADCs #2 and #3
+// 5.1.7  - Fix turntable broadcasts for non-movement activities and <JP> result
+// 5.1.6  - STM32F4xx native I2C driver added
 // 5.1.5  - Added turntable object and EXRAIL commands
 //        - <I ...>, <JO ...>, <JP ...> - turntable commands
 //        - DCC_TURNTABLE, EXTT_TURNTABLE, IFTTPOSITION, ONROTATE, ROTATE, ROTATE_DCC, TT_ADDPOSITION, WAITFORTT EXRAIL