Acks

Config.h

@@ -5,9 +5,12 @@ const byte MAIN_SIGNAL_PIN = 12;
 const byte MAIN_SIGNAL_PIN_ALT = 0;  // for hardware that flipflops signal pins 
 const byte MAIN_SENSE_PIN = A0;   
 const byte MAIN_SENSE_FACTOR=1; //  analgRead(MAIN_SENSE_PIN) * MAIN_SENSE_FACTOR = milliamps 
+const byte MAIN_BRAKE_PIN = 9;
 
 const byte PROG_POWER_PIN = 11;
 const byte PROG_SIGNAL_PIN = 13;
 const byte PROG_SIGNAL_PIN_ALT = 0;  // for hardware that flipflops signal pins 
 const byte PROG_SENSE_PIN = A1;
+const byte PROG_BRAKE_PIN = 10;
+
 const float PROG_SENSE_FACTOR=1; //  analgRead(PROG_SENSE_PIN) * PROG_SENSE_FACTOR = milliamps 

DCC.cpp

@@ -125,8 +125,7 @@ bool DCC::writeCVBit(int cv, byte bNum, bool bValue)  {
     bitWrite(message[2],4,1);              // change instruction code from Write Bit to Verify Bit
     DCCWaveform::progTrack.schedulePacket(message,sizeof(message),6);             // NMRA recommends 6 write or reset packets for decoder recovery time
   */
-
+ return true; // <<<< NOT  ACCURATE... see comment above 
-  return DCCWaveform::progTrack.getAck();
 }
 
 
@@ -141,8 +140,8 @@ int DCC::readCV(int cv)  {
   // get each bit individually
   for (int i = 0; i < 8; i++) {
     message[2] = 0xE8 + i;
-    DCCWaveform::progTrack.schedulePacket(message, sizeof(message), 4);               // NMRA recommends 5 read packets
+    bool one=DCCWaveform::progTrack.schedulePacketWithAck(message, sizeof(message), 4);     // NMRA recommends 5 read packets
-    value += (DCCWaveform::progTrack.getAck() << i);
+    value += one << i;
   }
 
   return verifyCV(cv, value) ? value : -1;
@@ -183,10 +182,8 @@ byte DCC::cv2(int cv)  {
 bool DCC::verifyCV(int cv, byte value) {
   byte message[] = { cv1(0x74, cv), cv2(cv), value};
   DIAG(F("\n\nVerifying cv %d = %d"), cv, value);
-  DCCWaveform::progTrack.schedulePacket(message, sizeof(message), 5);
+  return DCCWaveform::progTrack.schedulePacketWithAck(message, sizeof(message), 5);
-  return DCCWaveform::progTrack.getAck();
+  }
-}
-
 
 void  DCC::updateLocoReminder(int loco, byte tSpeed, bool forward) {
   // determine speed reg for this loco

DCCWaveform.cpp

@@ -207,37 +207,41 @@ void DCCWaveform::schedulePacket(const byte buffer[], byte byteCount, byte repea
   packetPending = true;
 }
 
+// Wait until there is no packet pending, then make this pending
+bool DCCWaveform::schedulePacketWithAck(const byte buffer[], byte byteCount, byte repeats) {
+  
+  if (isMainTrack) return false; 
+  int baseline=0;
+  for (int i=0;i<ACK_BASELINE_SAMPLES;i++) {
+    baseline += Hardware::getCurrentMilliamps(isMainTrack);
+  }
+  baseline/=ACK_BASELINE_SAMPLES;
+  int upTrigger=baseline+ACK_MIN_PULSE;
  
   
-bool DCCWaveform::getAck()
+  DIAG(F("\nACK baseline=%d upT=%d "),baseline, upTrigger);
-{
-
-  if (isMainTrack) return false; // cant do this on main track
   
+  schedulePacket(buffer,byteCount,repeats);
   while (packetPending); // wait until transmitter has started transmitting the message
+
   unsigned long timeout = millis() + ACK_TIMEOUT;
   int maxCurrent = 0;
   bool result = false;
   int upsamples = 0;
-  int downsamples = 0;
   
-  // Monitor looking for a reading high enough to be an ack
+
-  while (result == false && timeout > millis()) {
+  // Monitor looking for an ack signal rise of at least 60mA but keep going for the timeout 
+  while (timeout > millis()) {
+    int current = Hardware::getCurrentMilliamps(isMainTrack);
+    maxCurrent = max(maxCurrent, current);
+    if  (current>upTrigger) {
+      result=true;
       upsamples++;
-    int current = Hardware::getCurrentMilliamps(isMainTrack);
+    }
-    maxCurrent = max(maxCurrent, current);
-    result = current > ACK_MIN_PULSE;
     }
 
-  // Monitor current until ack signal dies back
-  if (result) while ( true) {
-      downsamples++;
-      int current = Hardware::getCurrentMilliamps(isMainTrack);
-      maxCurrent = max(maxCurrent, current);
-      if (current <= ACK_MAX_NOT_PULSE) break;
-    }
   // The following DIAG is really useful as it can show how long and how far the
   // current changes during an ACK from the decoder.
-  DIAG(F("\nack=%d  max=%d, up=%d, down=%d "), result, maxCurrent, upsamples, downsamples);
+  DIAG(F("ack=%d  max=%d, up=%d"), result, maxCurrent, upsamples);
   return result;
 }

DCCWaveform.h

@@ -8,9 +8,9 @@ const int  POWER_SAMPLE_OVERLOAD_WAIT = 4000;
 
 
 // ACK current analogRead values (vary depending on motor shield and cpu voltage)
+const int   ACK_BASELINE_SAMPLES = 250 ;  // current samples before sending ACKable request
 const int   ACK_TIMEOUT = 25 ;  // millis getAck is prepared to wait for a signal
-const int   ACK_MAX_NOT_PULSE = 40 ;  // current below which this is NOT a pulse any more
+const int   ACK_MIN_PULSE = 60 ;   // current above baseline which a pulse is recognised
-const int   ACK_MIN_PULSE = 50 ;   // current above which a pulse is recognised
 
 const int   PREAMBLE_BITS_MAIN = 20;
 const int   PREAMBLE_BITS_PROG = 22;
@@ -18,8 +18,6 @@ const int   PREAMBLE_BITS_PROG = 22;
 // Railcom settings
 const bool RAILCOM_CUTOUT = true;
 const byte RAILCOM_PREAMBLES_BEFORE_CUTOUT = 1; // how far into the preamble do we cutout
-const byte RAILCOM_PREAMBLES_SKIPPED_IN_CUTOUT = 5;
-const byte RAILCOM_BRAKE_PIN = 9;
 
 
 
@@ -46,9 +44,8 @@ class DCCWaveform {
     POWERMODE getPowerMode();
     void checkPowerOverload();
     void schedulePacket(const byte buffer[], byte byteCount, byte repeats);
+    bool schedulePacketWithAck(const byte buffer[], byte byteCount, byte repeats);
     volatile bool packetPending;
-    bool  startAckProcess();
-    bool  getAck();
 
 
   private:

Hardware.cpp

@@ -20,6 +20,9 @@ void Hardware::init() {
 void Hardware::setPower(bool isMainTrack, bool on) {
   digitalWrite(isMainTrack ? MAIN_POWER_PIN : PROG_POWER_PIN, on ? HIGH : LOW);
 }
+void Hardware::setBrake(bool isMainTrack, bool on) {
+  digitalWrite(isMainTrack ? MAIN_BRAKE_PIN : PROG_BRAKE_PIN, on ? LOW:HIGH);
+}
 
 void Hardware::setSignal(bool isMainTrack, bool high) {
   byte pin = isMainTrack ? MAIN_SIGNAL_PIN : PROG_SIGNAL_PIN;

Hardware.h

@@ -6,6 +6,7 @@ class Hardware {
     static void setPower(bool isMainTrack, bool on);
     static void setSignal(bool isMainTrack, bool high);
     static int  getCurrentMilliamps(bool isMainTrack);
+    static void setBrake(bool isMainTrack, bool on);
     static void setCallback(int duration,  void (*isr)());
     static void setSingleCallback(int duration,  void (*isr)());
     static void resetSingleCallback(int duration);