RailCom cutout for MAIN and PROG track

DCCWaveform.cpp

@@ -1,4 +1,5 @@
 /*
+ *  @ 2024 Arkadiusz Hahn 
  *  © 2021 Neil McKechnie
  *  © 2021 Mike S
  *  © 2021 Fred Decker
@@ -35,6 +36,8 @@
 DCCWaveform  DCCWaveform::mainTrack(PREAMBLE_BITS_MAIN, true);
 DCCWaveform  DCCWaveform::progTrack(PREAMBLE_BITS_PROG, false);
 
+bool DCCWaveform::supportsRailcom=false;
+bool DCCWaveform::useRailcom=false;
 
 // This bitmask has 9 entries as each byte is trasmitted as a zero + 8 bits.
 const byte bitMask[] = {0x00, 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01};
@@ -62,6 +65,20 @@ const bool signalTransform[]={
    /* WAVE_PENDING (should not happen) -> */ LOW};
 
 void DCCWaveform::begin() {
+  // supportsRailcom depends on hardware capability
+  supportsRailcom = TrackManager::isRailcomCapable();
+  // useRailcom is user switchable at run time. 
+  useRailcom=supportsRailcom;
+  
+  if (useRailcom) {
+    DIAG(F("Railcom is enabled"));
+  } else {
+    DIAG(F("Railcom is disabled"));
+  }
+
+  TrackManager::setCutout(false,false);
+  TrackManager::setPROGCutout(false,false);
+
   DCCTimer::begin(DCCWaveform::interruptHandler);     
 }
 
@@ -69,9 +86,24 @@ void DCCWaveform::loop() {
  // empty placemarker in case ESP32 needs something here 
 }
 
+
+bool DCCWaveform::setUseRailcom(bool on) {
+  if (!supportsRailcom) return false; 
+  useRailcom=on;
+  if (!on) {
+    // turn off any existing cutout 
+    TrackManager::setCutout(false);
+    TrackManager::setPROGCutout(false);
+  }
+  return true;
+}
+
+
 #pragma GCC push_options
 #pragma GCC optimize ("-O3")
 void DCCWaveform::interruptHandler() {
+  
+
   // call the timer edge sensitive actions for progtrack and maintrack
   // member functions would be cleaner but have more overhead
   byte sigMain= signalTransform[mainTrack.state];
@@ -84,15 +116,24 @@ void DCCWaveform::interruptHandler() {
   // Refresh the values in the ADCee object buffering the values of the ADC HW
   ADCee::scan();
 
+  // WAVE_START is at start of bit where we need to find
+  // out if this is an railcom start or stop time
+  if (useRailcom) {
+    if ((mainTrack.state==WAVE_START) || (mainTrack.state== WAVE_MID_1))  mainTrack.railcom2();
+    if ((progTrack.state==WAVE_START) || (progTrack.state== WAVE_MID_1))  progTrack.railcom2();
+  } 
+
   // Move on in the state engine
   mainTrack.state=stateTransform[mainTrack.state];    
   progTrack.state=stateTransform[progTrack.state];    
   
   // WAVE_PENDING means we dont yet know what the next bit is
-  if (mainTrack.state==WAVE_PENDING) mainTrack.interrupt2();  
+  if ((mainTrack.state==WAVE_PENDING) || (mainTrack.state== WAVE_START))  mainTrack.interrupt2();  
-  if (progTrack.state==WAVE_PENDING) progTrack.interrupt2();
+  if ((progTrack.state==WAVE_PENDING) || (progTrack.state == WAVE_START))  {
-  else DCCACK::checkAck(progTrack.getResets());
+    progTrack.interrupt2();
-
+  } else {
+    DCCACK::checkAck(progTrack.getResets());
+  } 
 }
 #pragma GCC pop_options
 
@@ -111,10 +152,38 @@ DCCWaveform::DCCWaveform( byte preambleBits, bool isMain) {
   // The +1 below is to allow the preamble generator to create the stop bit
   // for the previous packet. 
   requiredPreambles = preambleBits+1; 
+  requiredPreambles <<=1;  // double the number of preamble wave halves
+
+  remainingPreambles=0; 
   bytes_sent = 0;
   bits_sent = 0;
 }
 
+#pragma GCC push_options
+#pragma GCC optimize ("-O3")
+void DCCWaveform::railcom2() {
+  bool cutout;
+  if (remainingPreambles==(requiredPreambles-4)) { 
+    cutout=true;
+  } else if (remainingPreambles==(requiredPreambles-11)) {  
+    cutout=false;
+  } else {
+    return; // neither start or end of cutout, do nothing
+  }
+
+  if (isMainTrack) {
+    if (TrackManager::progTrackSyncMain) {// we are main track and synced so we take care of prog track as well
+        TrackManager::setPROGCutout(cutout,true);
+    }
+    TrackManager::setCutout(cutout,true);
+  } else {
+    if (!TrackManager::progTrackSyncMain) {// we are prog track and not synced so we take care of ourselves
+        TrackManager::setPROGCutout(cutout,true);
+    } 
+  }
+}
+#pragma GCC pop_options
+
 
 
 #pragma GCC push_options
@@ -125,14 +194,18 @@ void DCCWaveform::interrupt2() {
   //        or WAVE_HIGH_0 for a 0 bit.
 
   if (remainingPreambles > 0 ) {
+    if (state==WAVE_PENDING) {
       state=WAVE_MID_1;  // switch state to trigger LOW on next interrupt
+    }
     remainingPreambles--;
+  
     // 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.
     DCCTimer::updateMinimumFreeMemoryISR(22); 
     return;
   }
   
+  if (state==WAVE_PENDING) {
     // Wave has gone HIGH but what happens next depends on the bit to be transmitted
     // beware OF 9-BIT MASK  generating a zero to start each byte
     state=(transmitPacket[bytes_sent] & bitMask[bits_sent])? WAVE_MID_1 : WAVE_HIGH_0; 
@@ -174,6 +247,7 @@ void DCCWaveform::interrupt2() {
       }
     }  
   }
+}
 #pragma GCC pop_options
 
 // Wait until there is no packet pending, then make this pending

DCCWaveform.h

@@ -52,6 +52,11 @@ class DCCWaveform {
     static void loop();
     static DCCWaveform  mainTrack;
     static DCCWaveform  progTrack;
+    
+    static bool supportsRailcom;
+    static bool useRailcom;
+    static bool setUseRailcom(bool on); 
+    
     inline void clearRepeats() { transmitRepeats=0; }
 #ifndef ARDUINO_ARCH_ESP32
     inline void clearResets() { sentResetsSincePacket=0; }
@@ -87,6 +92,7 @@ class DCCWaveform {
 #endif
     static void interruptHandler();
     void interrupt2();
+    void railcom2();
     
     bool isMainTrack;
     // Transmission controller

MotorDriver.cpp

@@ -1,4 +1,4 @@
-/*
+/*  @ 2024 Arkadiusz Hahn 
  *  © 2022-2023 Paul M Antoine
  *  © 2021 Mike S
  *  © 2021 Fred Decker
@@ -32,6 +32,7 @@ unsigned long MotorDriver::globalOverloadStart = 0;
 volatile portreg_t shadowPORTA;
 volatile portreg_t shadowPORTB;
 volatile portreg_t shadowPORTC;
+volatile portreg_t shadowPORTH;
 
 MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, int16_t brake_pin,
                          byte current_pin, float sense_factor, unsigned int trip_milliamps, int16_t fault_pin) {
@@ -52,17 +53,17 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
 
   fastSignalPin.shadowinout = NULL;
   if (HAVE_PORTA(fastSignalPin.inout == &PORTA)) {
-    DIAG(F("Found PORTA pin %d"),signalPin);
+    DIAG(F("Found SignalPin PORTA pin %d"),signalPin);
     fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &shadowPORTA;
   }
   if (HAVE_PORTB(fastSignalPin.inout == &PORTB)) {
-    DIAG(F("Found PORTB pin %d"),signalPin);
+    DIAG(F("Found SignalPin PORTB pin %d"),signalPin);
     fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &shadowPORTB;
   }
   if (HAVE_PORTC(fastSignalPin.inout == &PORTC)) {
-    DIAG(F("Found PORTC pin %d"),signalPin);
+    DIAG(F("Found SignalPin PORTC pin %d"),signalPin);
     fastSignalPin.shadowinout = fastSignalPin.inout;
     fastSignalPin.inout = &shadowPORTC;
   }
@@ -75,17 +76,17 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
 
     fastSignalPin2.shadowinout = NULL;
     if (HAVE_PORTA(fastSignalPin2.inout == &PORTA)) {
-      DIAG(F("Found PORTA pin %d"),signalPin2);
+      DIAG(F("Found SignalPin2 PORTA pin %d"),signalPin2);
       fastSignalPin2.shadowinout = fastSignalPin2.inout;
       fastSignalPin2.inout = &shadowPORTA;
     }
     if (HAVE_PORTB(fastSignalPin2.inout == &PORTB)) {
-      DIAG(F("Found PORTB pin %d"),signalPin2);
+      DIAG(F("Found SignalPin2 PORTB pin %d"),signalPin2);
       fastSignalPin2.shadowinout = fastSignalPin2.inout;
       fastSignalPin2.inout = &shadowPORTB;
     }
     if (HAVE_PORTC(fastSignalPin2.inout == &PORTC)) {
-      DIAG(F("Found PORTC pin %d"),signalPin2);
+      DIAG(F("Found SignalPin2 PORTC pin %d"),signalPin2);
       fastSignalPin2.shadowinout = fastSignalPin2.inout;
       fastSignalPin2.inout = &shadowPORTC;
     }
@@ -102,6 +103,31 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
     getFastPin(F("BRAKE"),brakePin,fastBrakePin);
     // if brake is used for railcom  cutout we need to do PORTX register trick here as well
     pinMode(brakePin, OUTPUT);
+    fastBrakePin.shadowinout = NULL;
+
+   //DIAG(F("Found BrakePin %d "), brake_pin);
+    if (HAVE_PORTA(fastBrakePin.inout == &PORTA)) {
+      DIAG(F("Found BrakePin PORTA pin %d"),brakePin);
+      fastBrakePin.shadowinout = fastBrakePin.inout;
+      fastBrakePin.inout = &shadowPORTA;
+    }
+    if (HAVE_PORTB(fastBrakePin.inout == &PORTB)) {
+      DIAG(F("Found BrakePin PORTB pin %d"),brakePin);
+      fastBrakePin.shadowinout = fastBrakePin.inout;
+      fastBrakePin.inout = &shadowPORTB;
+    }
+    if (HAVE_PORTC(fastBrakePin.inout == &PORTC)) {
+      DIAG(F("Found BrakePin PORTC pin %d"),brakePin);
+      fastBrakePin.shadowinout = fastBrakePin.inout;
+      fastBrakePin.inout = &shadowPORTC;
+    }
+    if (HAVE_PORTH(fastBrakePin.inout == &PORTH)) {
+      DIAG(F("Found BrakePin PORTH pin %d"),brakePin);
+      fastBrakePin.shadowinout = fastBrakePin.inout;
+      fastBrakePin.inout = &shadowPORTH;
+    }
+
+    
     setBrake(true);  // start with brake on in case we hace DC stuff going on
   } else {
     brakePin=UNUSED_PIN;
@@ -170,6 +196,9 @@ bool MotorDriver::isPWMCapable() {
     return (!dualSignal) && DCCTimer::isPWMPin(signalPin); 
 }
 
+bool MotorDriver::isRailcomCapable() {
+    return (!dualSignal) && (brakePin!=UNUSED_PIN); 
+}
 
 void MotorDriver::setPower(POWERMODE mode) {
   if (powerMode == mode) return;
@@ -195,23 +224,6 @@ void MotorDriver::setPower(POWERMODE mode) {
   powerMode=mode; 
 }
 
-// setBrake applies brake if on == true. So to get
-// voltage from the motor bride one needs to do a
-// setBrake(false).
-// If the brakePin is negative that means the sense
-// of the brake pin on the motor bridge is inverted
-// (HIGH == release brake) and setBrake does
-// compensate for that.
-//
-void MotorDriver::setBrake(bool on, bool interruptContext) {
-  if (brakePin == UNUSED_PIN) return;
-  if (!interruptContext) {noInterrupts();}
-  if (on ^ invertBrake)
-    setHIGH(fastBrakePin);
-  else
-    setLOW(fastBrakePin);
-  if (!interruptContext) {interrupts();}
-}
 
 bool MotorDriver::canMeasureCurrent() {
   return currentPin!=UNUSED_PIN;
@@ -455,7 +467,7 @@ void  MotorDriver::getFastPin(const FSH* type,int pin, bool input, FASTPIN & res
       result.inout = portOutputRegister(port);
     result.maskHIGH = digitalPinToBitMask(pin);
     result.maskLOW = ~result.maskHIGH;
-    // DIAG(F(" port=0x%x, inoutpin=0x%x, isinput=%d, mask=0x%x"),port, result.inout,input,result.maskHIGH);
+    //DIAG(F("MotorDriver::getFastPin port=0x%x, inoutpin=0x%x, isinput=%d, mask=0x%x"),port, result.inout,input,result.maskHIGH);
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////

MotorDriver.h

@@ -43,6 +43,7 @@ enum TRACK_MODE : byte {TRACK_MODE_NONE = 1, TRACK_MODE_MAIN = 2, TRACK_MODE_PRO
 #define HAVE_PORTA(X) X
 #define HAVE_PORTB(X) X
 #define HAVE_PORTC(X) X
+#define HAVE_PORTH(X) X
 #endif
 #if defined(ARDUINO_AVR_UNO)
 #define HAVE_PORTB(X) X
@@ -74,7 +75,9 @@ enum TRACK_MODE : byte {TRACK_MODE_NONE = 1, TRACK_MODE_MAIN = 2, TRACK_MODE_PRO
 #ifndef HAVE_PORTC
 #define HAVE_PORTC(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
 #endif
-
+#ifndef HAVE_PORTH
+#define HAVE_PORTH(X) byte TOKENPASTE2(Unique_, __LINE__) __attribute__((unused)) =0
+#endif
 // Virtualised Motor shield 1-track hardware Interface
 
 #ifndef UNUSED_PIN     // sync define with the one in MotorDrivers.h
@@ -110,6 +113,7 @@ struct FASTPIN {
 extern volatile portreg_t shadowPORTA;
 extern volatile portreg_t shadowPORTB;
 extern volatile portreg_t shadowPORTC;
+extern volatile portreg_t shadowPORTH;
 
 enum class POWERMODE : byte { OFF, ON, OVERLOAD, ALERT };
 
@@ -118,35 +122,59 @@ class MotorDriver {
     
     MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, int16_t brake_pin, 
                 byte current_pin, float senseFactor, unsigned int tripMilliamps, int16_t fault_pin);
+    
     void setPower( POWERMODE mode);
+    
     POWERMODE getPower() { return powerMode;}
+    
     // as the port registers can be shadowed to get syncronized DCC signals
     // we need to take care of that and we have to turn off interrupts if
     // we setSignal() or setBrake() or setPower() during that time as
     // otherwise the call from interrupt context can undo whatever we do
     // from outside interrupt
-    void setBrake( bool on, bool interruptContext=false);
+    
+
+    // setBrake applies brake if on == true. So to get
+    // voltage from the motor bride one needs to do a
+    // setBrake(false).
+    // If the brakePin is negative that means the sense
+    // of the brake pin on the motor bridge is inverted
+    // (HIGH == release brake) and setBrake does
+    // compensate for that.   
+    __attribute__((always_inline)) inline void setBrake(bool on, bool interruptContext=false) {
+      if (brakePin == UNUSED_PIN) return;
+      if (!interruptContext) {noInterrupts();}
+      if (on ^ invertBrake) {
+        setHIGH(fastBrakePin);
+      } else {
+        setLOW(fastBrakePin);
+      }  
+      if (!interruptContext) {interrupts();}
+    };
+
+
     __attribute__((always_inline)) inline void setSignal( bool high) {
       if (trackPWM) {
 	      DCCTimer::setPWM(signalPin,high);
-      }
+      } else {
-      else {
 	    if (high) {
 	      setHIGH(fastSignalPin);
 	      if (dualSignal) setLOW(fastSignalPin2);
-	}
+	    } else {
-	else {
 	      setLOW(fastSignalPin);
 	      if (dualSignal) setHIGH(fastSignalPin2);
 	    }
       }
     };
+    
     inline void enableSignal(bool on) {
-      if (on)
+      if (on) {
 	      pinMode(signalPin, OUTPUT);
-      else
+      } else {
 	      pinMode(signalPin, INPUT);
+      }  
     };
+
     inline pinpair getSignalPin() { return pinpair(signalPin,signalPin2); };
     void setDCSignal(byte speedByte);
     void throttleInrush(bool on);
@@ -178,6 +206,7 @@ class MotorDriver {
 	    return rawCurrentTripValue;
     }
     bool isPWMCapable();
+    bool isRailcomCapable();
     bool canMeasureCurrent();
     bool trackPWM = false; // this track uses PWM timer to generate the DCC waveform
     bool commonFaultPin = false; // This is a stupid motor shield which has only a common fault pin for both outputs

TrackManager.cpp

@@ -1,4 +1,4 @@
-/*
+/*  @ 2024 Arkadiusz Hahn 
  *  © 2022 Chris Harlow
  *  © 2022 Harald Barth
  *  All rights reserved.
@@ -159,10 +159,41 @@ void TrackManager::setDCCSignal( bool on) {
   HAVE_PORTC(PORTC=shadowPORTC);
 }
 
-void TrackManager::setCutout( bool on) {
+// setCutout() for MAIN track 
-    (void) on;
+void TrackManager::setCutout( bool on,bool interruptContext) {
-    // TODO Cutout needs fake ports as well
+    //(void) on;  //  avoid compiler warning  -Wunused 
-    // TODO      APPLY_BY_MODE(TRACK_MODE_MAIN,setCutout(on));
+    // Cutout needs fake ports as well
+    HAVE_PORTA(shadowPORTA=PORTA);
+    HAVE_PORTB(shadowPORTB=PORTB);
+    HAVE_PORTC(shadowPORTC=PORTC);
+    HAVE_PORTH(shadowPORTH=PORTH);
+    APPLY_BY_MODE(TRACK_MODE_MAIN,setBrake(on,interruptContext));
+    HAVE_PORTA(PORTA=shadowPORTA);
+    HAVE_PORTB(PORTB=shadowPORTB);
+    HAVE_PORTC(PORTC=shadowPORTC);
+    HAVE_PORTH(PORTH=shadowPORTH);
+}
+
+void TrackManager::setPROGCutout( bool on,bool interruptContext) {
+    HAVE_PORTA(shadowPORTA=PORTA);
+    HAVE_PORTB(shadowPORTB=PORTB);
+    HAVE_PORTC(shadowPORTC=PORTC);
+    HAVE_PORTH(shadowPORTH=PORTH);
+    APPLY_BY_MODE(TRACK_MODE_PROG,setBrake(on,interruptContext));
+    HAVE_PORTA(PORTA=shadowPORTA);
+    HAVE_PORTB(PORTB=shadowPORTB);
+    HAVE_PORTC(PORTC=shadowPORTC);
+    HAVE_PORTH(PORTH=shadowPORTH);
+}
+
+// true when there is any railcom capable MAIN track
+bool TrackManager::isRailcomCapable() {
+  FOR_EACH_TRACK(t) {
+    if((track[t]->getMode()==TRACK_MODE_MAIN) && (track[t]->isRailcomCapable())){
+      return true;
+    }
+  }
+  return false;
 }
 
 // setPROGSignal(), called from interrupt context

TrackManager.h

@@ -51,9 +51,11 @@ class TrackManager {
                  );
     
     static void setDCCSignal( bool on);
-    static void setCutout( bool on);
     static void setPROGSignal( bool on);
     static void setDCSignal(int16_t cab, byte speedbyte);
+    static void setCutout( bool on,bool interruptContext=false);
+    static void setPROGCutout( bool on,bool interruptContext=false);
+    static bool isRailcomCapable();
     static MotorDriver * getProgDriver();
 #ifdef ARDUINO_ARCH_ESP32
   static std::vector<MotorDriver *>getMainDrivers();