From ffea04a499e836aab81216807968db906a350fa1 Mon Sep 17 00:00:00 2001
From: Asbelos <asbelos@btinternet.com>
Date: Tue, 16 Jun 2020 11:06:36 +0100
Subject: [PATCH] tIMER WRAP PROTECTION and broadcast speed fix

---
 DCC.cpp         | 12 +++++++++---
 DCC.h           |  2 +-
 DCCWaveform.cpp | 22 +++++++++++-----------
 DCCWaveform.h   |  3 ++-
 4 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/DCC.cpp b/DCC.cpp
index 45193b7..32c131f 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -272,8 +272,15 @@ byte DCC::cv2(int cv)  {
 
 
 void  DCC::updateLocoReminder(int loco, byte speedCode) {
-  // determine speed reg for this loco
   int reg;
+ 
+  if (loco==0) {
+     // broadcast message
+     for (reg = 0; reg < MAX_LOCOS; reg++) speedTable[reg].speedCode = speedCode;
+     return; 
+  }
+  
+  // determine speed reg for this loco
   int firstEmpty = MAX_LOCOS;
   for (reg = 0; reg < MAX_LOCOS; reg++) {
     if (speedTable[reg].loco == loco) break;
@@ -299,7 +306,7 @@ int   DCC::ackManagerCv;
 byte   DCC::ackManagerBitNum;
 bool   DCC::ackReceived;
 int   DCC::ackTriggerMilliamps;
-long   DCC::ackPulseStart;
+unsigned long   DCC::ackPulseStart;
 
 ACK_CALLBACK DCC::ackManagerCallback;
 
@@ -393,7 +400,6 @@ void DCC::ackManagerLoop() {
         if (ackPulseStart==0) return; // keep waiting for leading edge 
         { // detected trailing edge of pulse
           long pulseDuration=micros()-ackPulseStart;       
-          // TODO handle timer wrapover
           if (pulseDuration>4500 && pulseDuration<8000) {
             ackReceived=true;
             DCCWaveform::progTrack.killRemainingRepeats(); // probably no need after 8.5ms!!
diff --git a/DCC.h b/DCC.h
index e51fc49..80b45fb 100644
--- a/DCC.h
+++ b/DCC.h
@@ -72,7 +72,7 @@ private:
   static byte    ackManagerStash;
   static bool ackReceived;
   static int ackTriggerMilliamps;
-  static long ackPulseStart;
+  static unsigned long ackPulseStart;
   static ACK_CALLBACK  ackManagerCallback;
   static void ackManagerSetup(int cv, byte bitNumOrbyteValue, ackOp const program[], ACK_CALLBACK callback);
   static void ackManagerLoop();
diff --git a/DCCWaveform.cpp b/DCCWaveform.cpp
index f50b285..dcfb1d5 100644
--- a/DCCWaveform.cpp
+++ b/DCCWaveform.cpp
@@ -55,11 +55,12 @@ DCCWaveform::DCCWaveform( byte preambleBits, bool isMain) {
   requiredPreambles = preambleBits;
   bytes_sent = 0;
   bits_sent = 0;
-  nextSampleDue = 0;
-
+  sampleDelay = 0;
+  lastSampleTaken = millis();
 }
 void DCCWaveform::beginTrack() {
   setPowerMode(POWERMODE::ON);
+   
 }
 
 POWERMODE DCCWaveform::getPowerMode() {
@@ -74,32 +75,31 @@ void DCCWaveform::setPowerMode(POWERMODE mode) {
 
 
 void DCCWaveform::checkPowerOverload() {
-  if (millis() < nextSampleDue) return;
-  int delay;
-
+  if (millis() - lastSampleTaken  < sampleDelay) return;
+  lastSampleTaken = millis();
+  
   switch (powerMode) {
     case POWERMODE::OFF:
-      delay = POWER_SAMPLE_OFF_WAIT;
+      sampleDelay = POWER_SAMPLE_OFF_WAIT;
       break;
     case POWERMODE::ON:
       // Check current
       lastCurrent = Hardware::getCurrentMilliamps(isMainTrack);
-      if (lastCurrent < POWER_SAMPLE_MAX)  delay = POWER_SAMPLE_ON_WAIT;
+      if (lastCurrent < POWER_SAMPLE_MAX)  sampleDelay = POWER_SAMPLE_ON_WAIT;
       else {
         setPowerMode(POWERMODE::OVERLOAD);
         DIAG(F("\n*** %S TRACK POWER OVERLOAD current=%d max=%d ***\n"), isMainTrack ? F("MAIN") : F("PROG"), lastCurrent, POWER_SAMPLE_MAX);
-        delay = POWER_SAMPLE_OVERLOAD_WAIT;
+        sampleDelay = POWER_SAMPLE_OVERLOAD_WAIT;
       }
       break;
     case POWERMODE::OVERLOAD:
       // Try setting it back on after the OVERLOAD_WAIT
       setPowerMode(POWERMODE::ON);
-      delay = POWER_SAMPLE_ON_WAIT;
+      sampleDelay = POWER_SAMPLE_ON_WAIT;
       break;
     default:
-      delay = 999; // cant get here..meaningless statement to avoid compiler warning.
+      sampleDelay = 999; // cant get here..meaningless statement to avoid compiler warning.
   }
-  nextSampleDue = millis() + delay;
 }
 
 
diff --git a/DCCWaveform.h b/DCCWaveform.h
index fe86d75..284cdf6 100644
--- a/DCCWaveform.h
+++ b/DCCWaveform.h
@@ -78,6 +78,7 @@ class DCCWaveform {
     
     // current sampling
     POWERMODE powerMode;
-    unsigned long nextSampleDue;
+    unsigned long lastSampleTaken;
+    int sampleDelay;
 };
 #endif