detection happening!

DCCWaveform.cpp

@@ -77,6 +77,7 @@ void DCCWaveform::interruptHandler() {
   if (cutoutNextTime) {
     cutoutNextTime=false;
     railcomSampleWindow=false; // about to cutout, stop reading railcom data.
+    railcomCutoutCounter++;
     DCCTimer::startRailcomTimer(9);
   }
   byte sigMain=signalTransform[mainTrack.state];
@@ -125,6 +126,7 @@ bool DCCWaveform::railcomPossible=false;     // High accuracy only
 volatile bool DCCWaveform::railcomActive=false;     // switched on by user
 volatile bool DCCWaveform::railcomDebug=false;     // switched on by user
 volatile bool DCCWaveform::railcomSampleWindow=false; // true during packet transmit
+volatile byte DCCWaveform::railcomCutoutCounter=0;    // cyclic cutout
 
 bool DCCWaveform::setRailcom(bool on, bool debug) {
   if (on && railcomPossible) {

DCCWaveform.h

@@ -87,6 +87,9 @@ class DCCWaveform {
     inline static bool isRailcom() {
       return railcomActive;
     };
+    inline static byte getRailcomCutoutCounter() {
+      return railcomCutoutCounter;
+    };
     inline static bool isRailcomSampleWindow() {
       return railcomSampleWindow;
     };
@@ -125,6 +128,7 @@ class DCCWaveform {
     static volatile bool railcomActive;     // switched on by user
     static volatile bool railcomDebug;     // switched on by user
     static volatile bool railcomSampleWindow; // when safe to sample
+    static volatile byte railcomCutoutCounter; // incremented for each cutout
     static bool cutoutNextTime;   // railcom
 #ifdef ARDUINO_ARCH_ESP32
   static RMTChannel *rmtMainChannel;

IO_I2CRailcom.h

@@ -54,7 +54,7 @@
 
 // Debug and diagnostic defines, enable too many will result in slowing the driver
 #define DIAG_I2CRailcom
-#define DIAG_I2CRailcom_data
+//#define DIAG_I2CRailcom_data
 
 class I2CRailcom : public IODevice {
 private: 
@@ -62,6 +62,7 @@ private:
   uint8_t _UART_CH=0x00; // channel 0 or 1 flips each loop if npins>1
   byte _inbuf[65];
   byte _outbuf[2];
+  byte cutoutCounter[2]; 
   Railcom _channelMonitors[2];
   int16_t _locoInBlock[2]; 
 public:
@@ -87,6 +88,8 @@ public:
     DIAG(F("I2CRailcom: %s UART%S detected"), 
            _I2CAddress.toString(), exists?F(""):F(" NOT"));
     if (!exists) return;
+    _locoInBlock[0]=0;
+    _locoInBlock[1]=0;
   
     _UART_CH=0;
     Init_SC16IS752(); // Initialize UART0    
@@ -110,39 +113,43 @@ public:
     // IF we have 2 channels, flip channels each loop
     if (_nPins>1) _UART_CH=_UART_CH?0:1;
 
+    // have we read this cutout already?
+    auto cut=DCCWaveform::getRailcomCutoutCounter();
+    if (cutoutCounter[_UART_CH]==cut) return; 
+    cutoutCounter[_UART_CH]=cut; 
+    
     // Read incoming raw Railcom data, and process accordingly
 
     auto inlength = UART_ReadRegister(REG_RXLV);
     if (inlength==0) return; 
-    
-    #ifdef DIAG_I2CRailcom
-          DIAG(F("Railcom: %s/%d RX Fifo length: %d"),_I2CAddress.toString(), _UART_CH, inlength); 
-    #endif
-
-    // Read data buffer from UART
-    _outbuf[0]=(byte)(REG_RHR << 3 | _UART_CH << 1);
-    I2CManager.read(_I2CAddress, _inbuf, inlength, _outbuf, 1); 
-
+    if (inlength> sizeof(_inbuf)) inlength=sizeof(_inbuf); 
+    _inbuf[0]=0;
+    if (inlength>0) {
+      // Read data buffer from UART
+      _outbuf[0]=(byte)(REG_RHR << 3 | _UART_CH << 1);
+      I2CManager.read(_I2CAddress, _inbuf, inlength, _outbuf, 1); 
+    }
     // HK: Reset FIFO at end of read cycle
     UART_WriteRegister(REG_FCR, 0x07,false);
+    //if (inlength<2) return;  
 
     #ifdef DIAG_I2CRailcom_data
-      DIAG(F("Railcom %s/%d RX FIFO Data"), _I2CAddress.toString(), _UART_CH);
+      DIAG(F("Railcom %s/%d RX FIFO Data, %d"), _I2CAddress.toString(), _UART_CH,inlength);
       for (int i = 0; i < inlength; i++){
-        DIAG(F("[0x%x]: 0x%x"), i, _inbuf[i]);  
+        if (_inbuf[i])DIAG(F("[0x%x]: 0x%x"), i, _inbuf[i]);  
       }
     #endif
     
     // Ask Railcom to interpret the channel1 loco
     auto locoid=_channelMonitors[_UART_CH].getChannel1Loco(_inbuf);
-    #ifdef DIAG_I2CRailcom
-      DIAG(F("Railcom Channel1=%d"), locoid);
-    #endif
     if (locoid<0) return; // -1 indicates Railcom needs another packet
    
     // determine if loco in this block has changed 
     auto prevLoco=_locoInBlock[_UART_CH];
     if (locoid==prevLoco) return;
+    #ifdef DIAG_I2CRailcom
+      DIAG(F("Railcom vpin %d was %d is %d "), _firstVpin+_UART_CH, prevLoco, locoid);
+    #endif
     
     // Previous loco (if any) is exiting block  
     if (prevLoco) RMFT3::blockEvent(_firstVpin+_UART_CH,prevLoco,false);

Railcom.cpp

@@ -133,6 +133,7 @@ const uint8_t HIGHFLASH decode[256] =
 Railcom::Railcom() {
     haveHigh=false;
     haveLow=false;
+    packetsWithNoData=0;
 }
 
     /* returns -1: Call again next packet
@@ -141,9 +142,7 @@ Railcom::Railcom() {
     */
 int16_t Railcom::getChannel1Loco(uint8_t * inbound) {
     auto v1=GETHIGHFLASH(decode,inbound[0]);
-    if (v1>MAX_VALID) return -1;
     auto v2=GETHIGHFLASH(decode,inbound[1]);
-    if (v2>MAX_VALID) return -1;
     auto packet=(v1<<6) | v2;
     // packet is 12 bits TTTTDDDDDDDD
     auto type=packet>>8;   
@@ -151,18 +150,24 @@ int16_t Railcom::getChannel1Loco(uint8_t * inbound) {
     if (type==RMOB_ADRHIGH) {
         holdoverHigh=data;
         haveHigh=true;
+        packetsWithNoData=0;
         }
     else if (type==RMOB_ADRLOW) {
         holdoverLow=data;
         haveLow=true;
+        packetsWithNoData=0;
         }
     else if (type==RMOB_EXT) {
         return -1; /* ignore*/
         }
     else {
-        haveHigh=false;
-        haveLow=false;
-        return 0; // treat as no loco 
+        if (packetsWithNoData>MAX_WAIT_FOR_GLITCH) {
+            haveHigh=false;
+            haveLow=false;
+            return 0; // treat as no loco
+        }
+        packetsWithNoData++;
+        return -1; // need more data          
     }    
     if (haveHigh && haveLow) return ((holdoverHigh<<8)| holdoverLow);
     return -1; // call again, need next packet 

Railcom.h

@@ -34,7 +34,9 @@ class Railcom {
 
   private:
  uint8_t holdoverHigh,holdoverLow;
-bool haveHigh,haveLow;  
+ bool haveHigh,haveLow; 
+ uint8_t packetsWithNoData;  
+ static const byte MAX_WAIT_FOR_GLITCH=10; // number of dead or empty packets before assuming loco=0 
 };
 
 #endif