STM32 DCCEXanalogWrite for TrackManager PWM

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
@@ -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
+// On STM32F4xx models that have them, Timers 6 and 7 have no PWM output capability,
-// this libary, we should be free and clear.
+// so are good choices for general timer duties - they are used for tone and servo
-HardwareTimer timer(TIM11);
+// 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);
+  dcctimer.pause();
-  timer.pause();
+  dcctimer.setPrescaleFactor(1);
-  timer.setPrescaleFactor(1);
 //  timer.setOverflow(CLOCK_CYCLES * 2);
-  timer.setOverflow(DCC_SIGNAL_TIME, MICROSEC_FORMAT);
+  dcctimer.setOverflow(DCC_SIGNAL_TIME, MICROSEC_FORMAT);
-  timer.attachInterrupt(Timer11_Handler);
+  // dcctimer.attachInterrupt(Timer11_Handler);
-  timer.refresh();
+  dcctimer.attachInterrupt(DCCTimer_Handler);
-  timer.resume();
+  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;
 }
 
@@ -235,6 +252,78 @@ void DCCTimer::reset() {
     while(true) {};
 }
 
+// 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};
+
+// 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));
+
+    // 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
 

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__)
+#if defined(ARDUINO_ARCH_ESP32)
-      // TODO: on ARM we can use digitalPinHasPWM, and may wish/need to
+      return (brakePin != UNUSED_PIN); // This was just (true) but we probably do need to check for UNUSED_PIN!
-      return true;
+#elif defined(__arm__)
-#else
+      // On ARM we can use digitalPinHasPWM
-#ifdef digitalPinToTimer
+      return ((brakePin!=UNUSED_PIN) && (digitalPinHasPWM(brakePin)));
+#elif defined(digitalPinToTimer)
       return ((brakePin!=UNUSED_PIN) && (digitalPinToTimer(brakePin)));
 #else
       return (brakePin<14 && brakePin >1);
-#endif //digitalPinToTimer
+#endif
-#endif //ESP32/ARM
     }
     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

version.h

@@ -3,7 +3,12 @@
 
 #include "StringFormatter.h"
 
-#define VERSION "5.1.9"
+#define VERSION "5.1.10"
+// 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