Not working

DCCTimer.cpp

@@ -75,6 +75,11 @@ INTERRUPT_CALLBACK interruptHandler=0;
        (void) pin; 
        return false;  // TODO what are the relevant pins? 
   }
+  
+  bool DCCTimer::isPWMPin(byte pin) {
+       (void) pin; 
+       return false;  // TODO what are the relevant pins? 
+  }
 
  void DCCTimer::setPWM(byte pin, bool high) {
     (void) pin;
@@ -104,6 +109,12 @@ INTERRUPT_CALLBACK interruptHandler=0;
        return false;  // TODO what are the relevant pins? 
   }
 
+  bool DCCTimer::isRailcomPin(byte pin) {
+       //Teensy: digitalPinHasPWM, todo
+      (void) pin;
+       return false;  // TODO what are the relevant pins? 
+  }
+
  void DCCTimer::setPWM(byte pin, bool high) {
     // TODO what are the relevant pins?
     (void) pin;
@@ -152,7 +163,11 @@ void DCCTimer::read(uint8_t word, uint8_t *mac, uint8_t offset) {
     #define TIMER1_A_PIN   11
     #define TIMER1_B_PIN   12
     #define TIMER1_C_PIN   13
-#else
+    //railcom timer facility
+  //  #define TIMER4_A_PIN   6
+    #define TIMER4_B_PIN   7
+    #define TIMER4_C_PIN   8
+ #else
    #define TIMER1_A_PIN   9
    #define TIMER1_B_PIN   10
 #endif
@@ -166,6 +181,16 @@ void DCCTimer::read(uint8_t word, uint8_t *mac, uint8_t offset) {
     TCNT1 = 0;   
     TCCR1B = _BV(WGM13) | _BV(CS10);     // Mode 8, clock select 1
     TIMSK1 = _BV(TOIE1); // Enable Software interrupt
+    
+    #if defined(TIMER4_A_PIN)
+      //railcom timer facility
+      TCCR4A = 0;
+      ICR4 = CLOCK_CYCLES;
+      TCNT4 = CLOCK_CYCLES/2;  // this timer fires half cycle after Timer 1     
+      TCCR4B = _BV(WGM13) | _BV(CS10);     // Mode 8, clock select 1
+      TIMSK4 = 0; // Disable Software interrupt
+      #endif
+
     interrupts();
   }
 
@@ -181,20 +206,49 @@ void DCCTimer::read(uint8_t word, uint8_t *mac, uint8_t offset) {
        #endif       
        ;
   }
+// Alternative pin manipulation via PWM control.
+  bool DCCTimer::isRailcomPin(byte pin) {
+       return 
+       #ifdef TIMER4_A_PIN 
+              pin==TIMER4_A_PIN ||
+              pin==TIMER4_B_PIN ||
+              pin==TIMER4_C_PIN ||
+       #endif       
+              false;
+  }
 
  void DCCTimer::setPWM(byte pin, bool high) {
+    byte val=high?1024:0;
     if (pin==TIMER1_A_PIN) {
       TCCR1A |= _BV(COM1A1);
-      OCR1A= high?1024:0;
+      OCR1A= val;
     }
     else if (pin==TIMER1_B_PIN) { 
       TCCR1A |= _BV(COM1B1);
-      OCR1B= high?1024:0;
+      OCR1B= val;
     }
  #ifdef TIMER1_C_PIN 
     else if (pin==TIMER1_C_PIN) { 
       TCCR1A |= _BV(COM1C1);
-      OCR1C= high?1024:0;
+      OCR1C= val;
+    }
+ #endif       
+ #ifdef TIMER4_A_PIN 
+    else if (pin==TIMER4_A_PIN) { 
+      TCCR4A |= _BV(COM4A1); //??????????????????????????????????
+      OCR4A= val;
+    }
+ #endif       
+ #ifdef TIMER4_B_PIN 
+    else if (pin==TIMER4_B_PIN) { 
+      TCCR4B |= _BV(COM4B1); //??????????????????????????????????
+      OCR4B= val;
+    }
+ #endif       
+ #ifdef TIMER4_C_PIN 
+    else if (pin==TIMER4_C_PIN) { 
+      TCCR4C |= _BV(COM4C1); //??????????????????????????????????
+      OCR4C= val;
     }
  #endif       
  }

DCCTimer.h

@@ -9,6 +9,7 @@ class DCCTimer {
   static void begin(INTERRUPT_CALLBACK interrupt);
   static void getSimulatedMacAddress(byte mac[6]);
   static bool isPWMPin(byte pin);
+  static bool isRailcomPin(byte pin);
   static void setPWM(byte pin, bool high);
 #if (defined(TEENSYDUINO) && !defined(__IMXRT1062__))
   static void read_mac(byte mac[6]);

DCCWaveform.cpp

@@ -46,8 +46,12 @@ void DCCWaveform::begin(MotorDriver * mainDriver, MotorDriver * progDriver) {
 				 && (mainDriver->getFaultPin() != UNUSED_PIN));
   // Only use PWM if both pins are PWM capable. Otherwise JOIN does not work
   MotorDriver::usePWM= mainDriver->isPWMCapable() && progDriver->isPWMCapable();
-  if (MotorDriver::usePWM)
+  MotorDriver::useRailcom= MotorDriver::usePWM && mainDriver->isRailcomCapable() && progDriver->isRailcomCapable();
+  
+  if (MotorDriver::usePWM){
     DIAG(F("Signal pin config: high accuracy waveform"));
+    if (MotorDriver::useRailcom) DIAG(F("Railcom Enabled"));
+  }
   else
     DIAG(F("Signal pin config: normal accuracy waveform"));
   DCCTimer::begin(DCCWaveform::interruptHandler);     
@@ -205,6 +209,10 @@ void DCCWaveform::interrupt2() {
   if (remainingPreambles > 0 ) {
     state=WAVE_MID_1;  // switch state to trigger LOW on next interrupt
     remainingPreambles--;
+    // Railcom cutout
+    if (remainingPreambles==requiredPreambles-2) motorDriver->setRailcomCutout(true);
+    else if (remainingPreambles==requiredPreambles-4) motorDriver->setRailcomCutout(false);
+     
     // Update free memory diagnostic as we don't have anything else to do this time.
     // Allow for checkAck and its called functions using 22 bytes more.
     updateMinimumFreeMemory(22); 

MotorDriver.cpp

@@ -27,6 +27,8 @@
 #define isLOW(fastpin)    (!isHIGH(fastpin))
 
 bool MotorDriver::usePWM=false;
+bool MotorDriver::useRailcom=false;
+
 bool MotorDriver::commonFaultPin=false;
        
 MotorDriver::MotorDriver(byte power_pin, byte signal_pin, byte signal_pin2, int8_t brake_pin,
@@ -84,6 +86,10 @@ bool MotorDriver::isPWMCapable() {
     return (!dualSignal) && DCCTimer::isPWMPin(signalPin); 
 }
 
+bool MotorDriver::isRailcomCapable() {
+    return (!dualSignal) && DCCTimer::isRailcomPin(brakePin); 
+}
+
 
 void MotorDriver::setPower(bool on) {
   if (on) {
@@ -110,6 +116,10 @@ void MotorDriver::setBrake(bool on) {
   else setLOW(fastBrakePin);
 }
 
+void MotorDriver::setRailcomCutout(bool on) {
+  if (useRailcom) DCCTimer::setPWM(brakePin,on);
+}
+
 void MotorDriver::setSignal( bool high) {
    if (usePWM) {
     DCCTimer::setPWM(signalPin,high);

MotorDriver.h

@@ -54,8 +54,11 @@ class MotorDriver {
 	    return rawCurrentTripValue;
     }
     bool isPWMCapable();
+    bool isRailcomCapable();
     bool canMeasureCurrent();
+    void setRailcomCutout(bool on);
     static bool usePWM;
+    static bool useRailcom;
     static bool commonFaultPin; // This is a stupid motor shield which has only a common fault pin for both outputs
     inline byte getFaultPin() {
 	return faultPin;

MotorDrivers.h

@@ -27,6 +27,11 @@
                               new MotorDriver(3, 12, UNUSED_PIN, UNUSED_PIN, A0, 2.99, 2000, UNUSED_PIN), \
                               new MotorDriver(11, 13, UNUSED_PIN, UNUSED_PIN, A1, 2.99, 2000, UNUSED_PIN)
 
+// Arduino standard Motor Shield with railcom (mega brakes on 6,7 require jumpers )
+#define STANDARD_WITH_RAILCOM F("STANDARD_WITH_RAILCOM"),                                                 \
+                              new MotorDriver(3, 12, UNUSED_PIN, 6, A0, 2.99, 2000, UNUSED_PIN), \
+                              new MotorDriver(11, 13, UNUSED_PIN, 7, A1, 2.99, 2000, UNUSED_PIN)
+
 // Pololu Motor Shield
 #define POLOLU_MOTOR_SHIELD F("POLOLU_MOTOR_SHIELD"),                                                 \
                             new MotorDriver( 9, 7, UNUSED_PIN,         -4, A0, 18, 3000, 12), \