SC16IS750 test and test on mux

Tested SC16IS750 (single channel UART) for compatibility Tested on PCA9548 mux Both successful
Update IO_I2CDFPlayer.h
2025-07-28 18:03:45 +02:00 · 2024-02-03 15:16:09 +00:00 · 2024-01-01 20:39:37 +00:00 · 2024-01-01 20:35:39 +00:00 · 2023-12-30 20:51:35 +00:00 · 2023-12-29 22:11:40 +00:00
12 changed files with 11651 additions and 2 deletions
--- a/5407
+++ b/5407
--- a/EXRAIL2.h
+++ b/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.
--- a/I2CManager.cpp
+++ b/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("?");
 }
@@ -363,4 +366,4 @@ void I2CAddress::toHex(const uint8_t value, char *buffer) {

 /* static */ bool I2CAddress::_addressWarningDone = false;

-#endif
+#endif
--- a/IODevice.h
+++ b/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
--- a/IO_I2CDFPlayer-test.h
+++ b/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
--- a/IO_I2CDFPlayer-test2.h
+++ b/IO_I2CDFPlayer-test2.h
--- a/IO_I2CDFPlayer-test3.h
+++ b/IO_I2CDFPlayer-test3.h
--- a/IO_I2CDFPlayer-test4.h
+++ b/IO_I2CDFPlayer-test4.h
--- a/IO_I2CDFPlayer-test5.h
+++ b/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
--- a/IO_I2CDFPlayer.h
+++ b/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
--- a/IO_Template.h
+++ b/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
--- a/myHal.cpp_example.txt
+++ b/myHal.cpp_example.txt
@@ -234,6 +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.
  //=======================================================================
Author	SHA1	Message	Date
kempe63	74c5a974e2	SC16IS750 test and test on mux Tested SC16IS750 (single channel UART) for compatibility Tested on PCA9548 mux Both successful	2024-02-03 15:16:09 +00:00
kempe63	0e9caa11c8	Update IO_I2CDFPlayer.h Oops, fixed a typo	2024-01-01 20:39:37 +00:00
kempe63	46673007cc	Update IO_I2CDFPlayer.h Added SETAM, set the audio Mixer command to the supported EX-Rail commands. the audio mixer can now be set at startup by using the configuration in myHall.cpp and it can be modified in an EX-Rail scripts. Syntax: PLAYSOUND(<vPin>, 0, <am>, SETAM) Valid values for <am>: 1 or 2	2024-01-01 20:35:39 +00:00
kempe63	c468979501	Update IO_I2CDFPlayer.h Cleaned up the code and tested again. This is ready to be merged into the devel branch when documentation is finished	2023-12-30 20:51:35 +00:00
kempe63	0feb2c74e7	Update IO_I2CDFPlayer.h Completed implementation of exposing most relevant DFPlayer commands Fixed a problem with RX corrupted data from DFPlayer. Added retry (currently max retry 3) after timeout and recovery Note: Need to think of a more elegant way to recover from a reset command	2023-12-29 22:11:40 +00:00
kempe63	e74c619fac	Merge branch 'I2CDFplayer' of https://github.com/DCC-EX/CommandStation-EX into I2CDFplayer	2023-12-27 17:34:43 +00:00
kempe63	32ecbbe147	Update IO_I2CDFPlayer.h Implented more DFPlayer commands	2023-12-27 17:31:31 +00:00
kempe63	b8e0185540	Update IO_I2CDFPlayer.h Further tweaks and cleanup	2023-11-12 20:03:41 +00:00
kempe63	5e0cf8eb74	Update myHal.cpp_example.txt Added IO_I2CDFPlayer example	2023-11-12 20:02:01 +00:00
kempe63	44ce1c0cfa	Preliminary working version of I2CDFPlayer Working, need some endurance testing and testing at scale	2023-11-12 12:14:02 +00:00
kempe63	22b066c400	Initial submit I2CDFPlayer	2023-11-05 15:57:58 +00:00