Merge branch 'AdvancedCVAck' into ESP32-IRAM_ATTR

* AdvancedCVAck:
  split out ServiceMode ackCV from Ops Mode AdvancedCVAck as doing a ackCV in Ops Mode is wrong and adds 6ms busy delay add cache of CV29 value
  bumped version to 2.0.2
  reverted changes around lastMicros
  added conditional compilation for ESP8266 to add ICACHE_RAM_ATTR to ExternalInterruptHandler changed storage for Micros to unsigned long
  changed the version to 201 in the header

# Conflicts:
#	NmraDcc.cpp
reverted to unsigned int

.gitignore

@@ -1,2 +0,0 @@
-.development
-*.zip

NmraDcc.cpp

@@ -2,21 +2,11 @@
 //
 // Model Railroading with Arduino - NmraDcc.cpp 
 //
-// Copyright (c) 2008 - 2020 Alex Shepherd
+// Copyright (c) 2008 - 2017 Alex Shepherd
 //
-// 	This library is free software; you can redistribute it and/or
-// 	modify it under the terms of the GNU Lesser General Public
-// 	License as published by the Free Software Foundation; either
-// 	version 2.1 of the License, or (at your option) any later version.
-// 
-// 	This library is distributed in the hope that it will be useful,
-// 	but WITHOUT ANY WARRANTY; without even the implied warranty of
-// 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// 	Lesser General Public License for more details.
-// 
-// 	You should have received a copy of the GNU Lesser General Public
-// 	License along with this library; if not, write to the Free Software
-// 	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+// This source file is subject of the GNU general public license 2,
+// that is available at the world-wide-web at
+// http://www.gnu.org/licenses/gpl.txt
 // 
 //------------------------------------------------------------------------
 //
@@ -37,7 +27,7 @@
 //                       Minor fixes to pass NMRA Baseline Conformance Tests.
 //            2018-12-17 added ESP32 support by Trusty (thierry@lapajaparis.net)
 //            2019-02-17 added ESP32 specific changes by Hans Tanner
-//            2020-05-15 changes to pass NMRA Tests ( always search for preamble )
+//
 //------------------------------------------------------------------------
 //
 // purpose:   Provide a simplified interface to decode NMRA DCC packets
@@ -46,10 +36,12 @@
 //------------------------------------------------------------------------
 
 #include "NmraDcc.h"
-#include "EEPROM.h"
+#ifdef __AVR_MEGA__
+#include <avr/eeprom.h>
+#endif
 
 // Uncomment to print DEBUG messages
-// #define DEBUG_PRINT		
+//#define DEBUG_PRINT		
 
 //------------------------------------------------------------------------
 // DCC Receive Routine
@@ -82,26 +74,19 @@
 //           DCC 1: _________XXXXXXXXX_________XXXXXXXXX_________
 //                           |<--------146us------>|
 //                           ^-INTx            ^-INTx
-//                           less than 146us: its a one-Bit
+//                           less than 138us: its a one-Bit
 //                                        
 //
 //                           |<-----------------232us----------->|
 //           DCC 0: _________XXXXXXXXXXXXXXXXXX__________________XXXXXXXX__________
 //                           |<--------146us------->|
 //                           ^-INTx                              ^-INTx
-//                           greater than 146us: its a zero bit
+//                           greater than 138us: its a zero bit
 //                                        
 //                                        
 //                                           
 //           
-
 //------------------------------------------------------------------------
-// if this is commented out, bit synchronisation is only done after a wrong checksum
-#define SYNC_ALWAYS
-
-// if this is commented out, Zero-Bit_Stretching is not supported
-// ( Bits longer than 2* MAX ONEBIT are treated as error )
-#define SUPPORT_ZERO_BIT_STRETCHING
 
 #define MAX_ONEBITFULL  146
 #define MAX_PRAEAMBEL   146 
@@ -192,7 +177,7 @@
         #define SET_TP3  GPOS = (1 << D7);
         #define CLR_TP3  GPOC = (1 << D7);
         #define MODE_TP4 pinMode( D8,OUTPUT ) ; // GPIO 15
-        #define SET_TP4  GPOS = (1 << D8);
+        #define SET_TP4  GPOC = (1 << D8);
         #define CLR_TP4  GPOC = (1 << D8);
     #elif defined(ESP32)
         #define MODE_TP1 pinMode( 33,OUTPUT ) ; // GPIO 33
@@ -205,7 +190,7 @@
         #define SET_TP3  GPOS = (1 << 26);
         #define CLR_TP3  GPOC = (1 << 26);
         #define MODE_TP4 pinMode( 27,OUTPUT ) ; // GPIO 27
-        #define SET_TP4  GPOS = (1 << 27);
+        #define SET_TP4  GPOC = (1 << 27);
         #define CLR_TP4  GPOC = (1 << 27);
         
         
@@ -261,17 +246,12 @@ static byte  ISRWatch;  // Interrupt Handler Edge Filter
 static byte  ISREdge;   // Holder of the Next Edge we're looking for: RISING or FALLING
 static byte  ISRWatch;  // Interrupt Handler Edge Filter 
 #endif
-byte ISRLevel;          // expected Level at DCC input during ISR ( to detect glitches )
-byte ISRChkMask;       // Flag if Level must be checked
 static word  bitMax, bitMin;
 
 typedef enum
 {
   WAIT_PREAMBLE = 0,
   WAIT_START_BIT,
-  #ifndef SYNC_ALWAYS
-  WAIT_START_BIT_FULL,
-  #endif
   WAIT_DATA,
   WAIT_END_BIT
 } 
@@ -292,7 +272,6 @@ struct DccRx_t
   uint8_t         DataReady ;
   uint8_t         BitCount ;
   uint8_t         TempByte ;
-  uint8_t         chkSum;
   DCC_MSG         PacketBuf;
   DCC_MSG         PacketCopy;
 } 
@@ -309,8 +288,6 @@ typedef struct
   DCC_MSG   LastMsg ;
   uint8_t	ExtIntNum; 
   uint8_t	ExtIntPinNum;
-  volatile uint8_t   *ExtIntPort;     // use port and bitmask to read input at AVR in ISR
-  uint8_t   ExtIntMask;     // digitalRead is too slow on AVR
   int16_t   myDccAddress;	// Cached value of DCC Address from CVs
   uint8_t   inAccDecDCCAddrNextReceivedMode;
   uint8_t	cv29Value; 
@@ -334,8 +311,6 @@ void ICACHE_RAM_ATTR ExternalInterruptHandler(void)
 void ExternalInterruptHandler(void)
 #endif
 {
-    SET_TP3;
-
 #ifdef ESP32
 //   switch (ISRWatch)
 //   {
@@ -363,7 +338,7 @@ void ExternalInterruptHandler(void)
     uint8_t DccBitVal;
     static int8_t  bit1, bit2 ;
     static unsigned int  lastMicros = 0;
-    static byte halfBit, DCC_IrqRunning, preambleBitCount;
+    static byte halfBit, DCC_IrqRunning;
     unsigned int  actMicros, bitMicros;
     #ifdef ALLOW_NESTED_IRQ
     if ( DCC_IrqRunning ) {
@@ -377,53 +352,17 @@ void ExternalInterruptHandler(void)
         return; //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> abort IRQ
     }
     #endif
+    SET_TP3;
     actMicros = micros();
     bitMicros = actMicros-lastMicros;
-
-        CLR_TP3; SET_TP3;
-#ifdef __AVR_MEGA__
-    if ( bitMicros < bitMin || ( DccRx.State != WAIT_START_BIT && (*DccProcState.ExtIntPort & DccProcState.ExtIntMask) != (ISRLevel) ) ) {
-#else
-    if ( bitMicros < bitMin || ( DccRx.State != WAIT_START_BIT && digitalRead( DccProcState.ExtIntPinNum ) != (ISRLevel) ) ) {
-#endif
-        // too short - my be false interrupt due to glitch or false protocol  or level does not match RISING / FALLING edge -> ignore this IRQ
+    if ( bitMicros < bitMin ) {
+        // too short - my be false interrupt due to glitch or false protocol -> ignore
         CLR_TP3;
-        SET_TP4; /*delayMicroseconds(1); */ CLR_TP4;
+        SET_TP4; CLR_TP4;
         return; //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> abort IRQ
     }
-        CLR_TP3;  SET_TP3;
-
-    lastMicros = actMicros;
-#ifndef SUPPORT_ZERO_BIT_STRETCHING
-    //if ( bitMicros > MAX_ZEROBITFULL ) {
-    if ( bitMicros > (bitMax*2) ) {
-        // too long - my be false protocol -> start over
-        DccRx.State = WAIT_PREAMBLE ;
-        DccRx.BitCount = 0 ;
-        preambleBitCount = 0;
-        // SET_TP2; CLR_TP2;
-        bitMax = MAX_PRAEAMBEL;
-        bitMin = MIN_ONEBITFULL;
-        #if defined ( __STM32F1__ )
-        detachInterrupt( DccProcState.ExtIntNum );
-        #endif
-        #ifdef ESP32
-        ISRWatch = ISREdge;
-        #else
-        attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, ISREdge );
-        #endif
-        // enable level-checking
-        ISRChkMask = DccProcState.ExtIntMask;
-        ISRLevel = (ISREdge==RISING)? DccProcState.ExtIntMask : 0 ;
-        CLR_TP3;
-        //CLR_TP3;
-        return; //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> abort IRQ
-    }
-        CLR_TP3;
-        SET_TP3;
-#endif
-    
     DccBitVal = ( bitMicros < bitMax );
+    lastMicros = actMicros;
     
     #ifdef ALLOW_NESTED_IRQ
     DCC_IrqRunning = true;
@@ -433,37 +372,43 @@ void ExternalInterruptHandler(void)
 #ifdef DCC_DEBUG
     DccProcState.TickCount++;
 #endif
+
   switch( DccRx.State )
   {
   case WAIT_PREAMBLE:
-    // We don't have to do anything special - looking for a preamble condition is done always
-    SET_TP2;
-    break;
+    if( DccBitVal )
+    {
+        SET_TP1;
+      DccRx.BitCount++;
+     if( DccRx.BitCount > 10 ) {
+        DccRx.State = WAIT_START_BIT ;
+        // While waiting for the start bit, detect halfbit lengths. We will detect the correct
+        // sync and detect whether we see a false (e.g. motorola) protocol
 
-#ifndef SYNC_ALWAYS
-  case WAIT_START_BIT_FULL:
-    // wait for startbit without level checking
-    if ( !DccBitVal ) {
-        // we got the startbit
-        CLR_TP2;CLR_TP1;
-        DccRx.State = WAIT_DATA ;
+    #if defined ( __STM32F1__ )
+		detachInterrupt( DccProcState.ExtIntNum );
+		#endif
+        #ifdef ESP32
+		ISRWatch = CHANGE;
+        #else
+        attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, CHANGE);
+        #endif
+        halfBit = 0;
+        bitMax = MAX_ONEBITHALF;
+        bitMin = MIN_ONEBITHALF;
         CLR_TP1;
-        // initialize packet buffer
-        DccRx.PacketBuf.Size = 0;
-        /*for(uint8_t i = 0; i< MAX_DCC_MESSAGE_LEN; i++ )
-            DccRx.PacketBuf.Data[i] = 0;*/
-        DccRx.PacketBuf.PreambleBits = preambleBitCount;
+      }
+    } else {
+        SET_TP1;
         DccRx.BitCount = 0 ;
-        DccRx.chkSum = 0 ;
-        DccRx.TempByte = 0 ;
-        //SET_TP1;
+        CLR_TP1;
     }
     break;
-#endif    
+
   case WAIT_START_BIT:
     // we are looking for first half "0" bit after preamble
     switch ( halfBit ) {
-      case 0: 
+      case 0:  //SET_TP1;
         // check first part
         if ( DccBitVal ) {
             // is still 1-bit (Preamble)
@@ -471,22 +416,24 @@ void ExternalInterruptHandler(void)
             bit1=bitMicros;
         } else {
             // was "0" half bit, maybe the startbit
+			SET_TP1;
             halfBit = 4;
+			CLR_TP1;
         }
         break;
-      case 1: // previous halfbit was '1'
+      case 1: //SET_TP1; // previous halfbit was '1'
         if ( DccBitVal ) {
             // its a '1' halfBit -> we are still in the preamble
             halfBit = 0;
             bit2=bitMicros;
-            preambleBitCount++;
+            DccRx.BitCount++;
             if( abs(bit2-bit1) > MAX_BITDIFF ) {
                 // the length of the 2 halfbits differ too much -> wrong protokoll
                 DccRx.State = WAIT_PREAMBLE;
                 bitMax = MAX_PRAEAMBEL;
                 bitMin = MIN_ONEBITFULL;
-                preambleBitCount = 0;
-                // SET_TP2; CLR_TP2;
+                DccRx.BitCount = 0;
+
         #if defined ( __STM32F1__ )
 				detachInterrupt( DccProcState.ExtIntNum );
 				#endif
@@ -494,9 +441,6 @@ void ExternalInterruptHandler(void)
 				ISRWatch = ISREdge;
                 #else
                 attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, ISREdge );
-                // enable level checking ( with direct port reading @ AVR )
-                ISRChkMask = DccProcState.ExtIntMask;       
-                ISRLevel = (ISREdge==RISING)? DccProcState.ExtIntMask : 0 ;
                 #endif
 				SET_TP3;
 				CLR_TP4;
@@ -509,33 +453,30 @@ void ExternalInterruptHandler(void)
 			SET_TP3;
         }
         break;
-      case 3: // previous halfbit was '0'  in second halfbit  
+      case 3: //SET_TP1;  // previous halfbit was '0'  in second halfbit  
         if ( DccBitVal ) {
             // its a '1' halfbit -> we got only a half '0' bit -> cannot be DCC
             DccRx.State = WAIT_PREAMBLE;
             bitMax = MAX_PRAEAMBEL;
             bitMin = MIN_ONEBITFULL;
-            preambleBitCount = 0;
-            // SET_TP2; CLR_TP2;
+            DccRx.BitCount = 0;
         } else {
             // we got two '0' halfbits -> it's the startbit
             // but sync is NOT ok, change IRQ edge.
-            CLR_TP2;CLR_TP1;
             if ( ISREdge == RISING ) ISREdge = FALLING; else ISREdge = RISING;
             DccRx.State = WAIT_DATA ;
-            CLR_TP1;
             bitMax = MAX_ONEBITFULL;
             bitMin = MIN_ONEBITFULL;
             DccRx.PacketBuf.Size = 0;
-            /*for(uint8_t i = 0; i< MAX_DCC_MESSAGE_LEN; i++ )
-            DccRx.PacketBuf.Data[i] = 0;*/
-            DccRx.PacketBuf.PreambleBits = preambleBitCount;
+            DccRx.PacketBuf.PreambleBits = 0;
+            for(uint8_t i = 0; i< MAX_DCC_MESSAGE_LEN; i++ )
+            DccRx.PacketBuf.Data[i] = 0;
+
+            DccRx.PacketBuf.PreambleBits = DccRx.BitCount;
             DccRx.BitCount = 0 ;
-            DccRx.chkSum = 0 ;
             DccRx.TempByte = 0 ;
-            //SET_TP1;
         }
-		//SET_TP4;
+		SET_TP4;
 
 			#if defined ( __STM32F1__ )
 			detachInterrupt( DccProcState.ExtIntNum );
@@ -545,40 +486,34 @@ void ExternalInterruptHandler(void)
             #else
 			attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, ISREdge );
             #endif
-        // enable level-checking
-        ISRChkMask = DccProcState.ExtIntMask;
-        ISRLevel = (ISREdge==RISING)? DccProcState.ExtIntMask : 0 ;
-        //CLR_TP4;
+        CLR_TP1;
+		CLR_TP4;
         break;
-      case 4: // previous (first) halfbit was 0
+      case 4: SET_TP1; // previous (first) halfbit was 0
         // if this halfbit is 0 too, we got the startbit
         if ( DccBitVal ) {
             // second halfbit is 1 -> unknown protokoll
             DccRx.State = WAIT_PREAMBLE;
             bitMax = MAX_PRAEAMBEL;
             bitMin = MIN_ONEBITFULL;
-            preambleBitCount = 0;
-            CLR_TP2;CLR_TP1;
             DccRx.BitCount = 0;
         } else {
             // we got the startbit
-            CLR_TP2;CLR_TP1;
             DccRx.State = WAIT_DATA ;
-            CLR_TP1;
             bitMax = MAX_ONEBITFULL;
             bitMin = MIN_ONEBITFULL;
-            // initialize packet buffer
             DccRx.PacketBuf.Size = 0;
-            /*for(uint8_t i = 0; i< MAX_DCC_MESSAGE_LEN; i++ )
-            DccRx.PacketBuf.Data[i] = 0;*/
-            DccRx.PacketBuf.PreambleBits = preambleBitCount;
+            DccRx.PacketBuf.PreambleBits = 0;
+            for(uint8_t i = 0; i< MAX_DCC_MESSAGE_LEN; i++ )
+            DccRx.PacketBuf.Data[i] = 0;
+
+            DccRx.PacketBuf.PreambleBits = DccRx.BitCount;
             DccRx.BitCount = 0 ;
-            DccRx.chkSum = 0 ;
             DccRx.TempByte = 0 ;
-            //SET_TP1;
         }
 		
-        //SET_TP4;
+        CLR_TP1;
+		SET_TP4;
 
 		#if defined ( __STM32F1__ )
 		detachInterrupt( DccProcState.ExtIntNum );
@@ -588,18 +523,14 @@ void ExternalInterruptHandler(void)
         #else
 		attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, ISREdge );
         #endif
-        // enable level-checking
-        ISRChkMask = DccProcState.ExtIntMask;
-        ISRLevel = (ISREdge==RISING)? DccProcState.ExtIntMask : 0 ;
 
-		//CLR_TP4;
+		CLR_TP4;
         break;
             
     }        
     break;
 
   case WAIT_DATA:
-    CLR_TP2;
     DccRx.BitCount++;
     DccRx.TempByte = ( DccRx.TempByte << 1 ) ;
     if( DccBitVal )
@@ -618,44 +549,30 @@ void ExternalInterruptHandler(void)
       {
         DccRx.State = WAIT_END_BIT ;
         DccRx.PacketBuf.Data[ DccRx.PacketBuf.Size++ ] = DccRx.TempByte ;
-        DccRx.chkSum ^= DccRx.TempByte;
       }
     }
     break;
 
   case WAIT_END_BIT:
-    SET_TP2;CLR_TP2;
     DccRx.BitCount++;
-    if( DccBitVal ) { // End of packet?
-      CLR_TP3; SET_TP4;
+    if( DccBitVal ) // End of packet?
+    {
+      CLR_TP3;
       DccRx.State = WAIT_PREAMBLE ;
       DccRx.BitCount = 0 ;
       bitMax = MAX_PRAEAMBEL;
       bitMin = MIN_ONEBITFULL;
-      SET_TP1;
-      if ( DccRx.chkSum == 0 ) { 
-        // Packet is valid
-        #ifdef ESP32
+#ifdef ESP32
 	  portENTER_CRITICAL_ISR(&mux);
-        #endif
+#endif
       DccRx.PacketCopy = DccRx.PacketBuf ;
       DccRx.DataReady = 1 ;
-        #ifdef ESP32
+#ifdef ESP32
 	  portEXIT_CRITICAL_ISR(&mux);
-        #endif
-        // SET_TP2; CLR_TP2;
-        preambleBitCount = 0 ;
-      } else {
-        // Wrong checksum
-        CLR_TP1;
-        #ifdef DCC_DBGVAR
-        DB_PRINT("Cerr");
-        countOf.Err++;
-        #endif
+#endif
+      SET_TP3;
     }
-
-      SET_TP3; CLR_TP4;
-    } else  { // Get next Byte
+    else  // Get next Byte
       // KGW - Abort immediately if packet is too long.
       if( DccRx.PacketBuf.Size == MAX_DCC_MESSAGE_LEN ) // Packet is too long - abort
       {
@@ -672,88 +589,31 @@ void ExternalInterruptHandler(void)
         DccRx.TempByte = 0 ;
       }
   }
-  }
-
-  // unless we're already looking for the start bit 
-  // we always search for a preamble ( ( 10 or more consecutive 1 bits )
-  // if we found it within a packet, the packet decoding is aborted because
-  // that much one bits cannot be valid in a packet.
-  if ( DccRx.State != WAIT_START_BIT ) {
-    if( DccBitVal )
-    {
-      preambleBitCount++;
-      //SET_TP2;
-      if( preambleBitCount > 10 ) {
-        CLR_TP2;
-#ifndef SYNC_ALWAYS
-        if ( DccRx.chkSum == 0 ) { 
-            // sync must be correct if chksum was ok, no need to check sync
-            DccRx.State = WAIT_START_BIT_FULL;
-        } else {
-#endif
-        DccRx.State = WAIT_START_BIT ;
-            SET_TP2;
-            // While waiting for the start bit, detect halfbit lengths. We will detect the correct
-            // sync and detect whether we see a false (e.g. motorola) protocol
-
-            #if defined ( __STM32F1__ )
-            detachInterrupt( DccProcState.ExtIntNum );
-            #endif
-            #ifdef ESP32
-            ISRWatch = CHANGE;
-            #else
-            attachInterrupt( DccProcState.ExtIntNum, ExternalInterruptHandler, CHANGE);
-            #endif
-            ISRChkMask = 0;         // AVR level check is always true with this settings
-            ISRLevel = 0;           // ( there cannot be false edge IRQ's with CHANGE )
-            halfBit = 0;
-            bitMax = MAX_ONEBITHALF;
-            bitMin = MIN_ONEBITHALF;
-            //CLR_TP1;
-#ifndef SYNC_ALWAYS
-        }
-#endif
-      }
-    } else {
-        CLR_TP1;
-        preambleBitCount = 0 ;
-        // SET_TP2; CLR_TP2;
-    }
-  }
-
   #ifdef ALLOW_NESTED_IRQ
   DCC_IrqRunning = false;
   #endif
-  //CLR_TP1;
+  CLR_TP1;
   CLR_TP3;
 }
 
 void ackCV(void)
 {
   if( notifyCVAck )
-  {
-    DB_PRINT("ackCV: Send Basic ACK");
     notifyCVAck() ;
-  }
 }
 
 void ackAdvancedCV(void)
 {
-  if( notifyAdvancedCVAck && (DccProcState.cv29Value & CV29_RAILCOM_ENABLE) )
-  {
-    DB_PRINT("ackAdvancedCV: Send RailCom ACK");
+  if( notifyAdvancedCVAck && (DccProcState.cv29Value & CV29_ADV_ACK) )
     notifyAdvancedCVAck() ;
-  }
 }
 
 
-uint8_t readEEPROM( unsigned int CV )
-{
+uint8_t readEEPROM( unsigned int CV ) {
     return EEPROM.read(CV) ;
 }
 
-void writeEEPROM( unsigned int CV, uint8_t Value )
-{
+void writeEEPROM( unsigned int CV, uint8_t Value ) {
     EEPROM.write(CV, Value) ;
   #if defined(ESP8266)
     EEPROM.commit();
@@ -763,17 +623,15 @@ void writeEEPROM( unsigned int CV, uint8_t Value )
   #endif
 }
 
-bool readyEEPROM()
-{
-#if defined ARDUINO_ARCH_MEGAAVR
-	return bit_is_clear(NVMCTRL.STATUS,NVMCTRL_EEBUSY_bp);
-#elif defined __AVR_MEGA__
+bool readyEEPROM() {
+    #ifdef __AVR_MEGA__
         return eeprom_is_ready();
-#else
+    #else
         return true;
-#endif
+    #endif
 }
 
+
 uint8_t validCV( uint16_t CV, uint8_t Writable )
 {
   if( notifyCVResetFactoryDefault && (CV == CV_MANUFACTURER_ID )  && Writable )
@@ -810,8 +668,6 @@ uint8_t writeCV( unsigned int CV, uint8_t Value)
   {
     case CV_29_CONFIG:
       // copy addressmode Bit to Flags
-      Value = Value &  ~CV29_RAILCOM_ENABLE;   // Bidi (RailCom) Bit must not be enabled, 
-                                            // because you cannot build a Bidi decoder with this lib.
       DccProcState.cv29Value = Value;
       DccProcState.Flags = ( DccProcState.Flags & ~FLAGS_CV29_BITS) | (Value & FLAGS_CV29_BITS);
       // no break, because myDccAdress must also be reset
@@ -863,7 +719,7 @@ uint16_t getMyAddr(void)
   return DccProcState.myDccAddress ;
 }
 
-void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void (*ackFunction)() )
+void processDirectOpsOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value )
 {
   // is it a Byte Operation
   if( Cmd & 0x04 )
@@ -873,9 +729,8 @@ void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void
     {
       if( validCV( CVAddr, 1 ) )
       {
-        DB_PRINT("CV: %d Byte Write: %02X", CVAddr, Value)
         if( writeCV( CVAddr, Value ) == Value )
-          ackFunction();
+          ackAdvancedCV();
       }
     }
 
@@ -883,9 +738,8 @@ void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void
     {  
       if( validCV( CVAddr, 0 ) )
       {
-        DB_PRINT("CV: %d Byte Read: %02X", CVAddr, Value)
         if( readCV( CVAddr ) == Value )
-          ackFunction();
+          ackAdvancedCV();
       }
     }
   }
@@ -898,8 +752,6 @@ void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void
 
     uint8_t tempValue = readCV( CVAddr ) ;  // Read the Current CV Value
 
-    DB_PRINT("CV: %d Current Value: %02X  Bit-Wise Mode: %s  Mask: %02X  Value: %02X", CVAddr, tempValue, BitWrite ? "Write":"Read", BitMask, BitValue);
-
     // Perform the Bit Write Operation
     if( BitWrite )
     {
@@ -912,7 +764,7 @@ void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void
           tempValue &= ~BitMask ;  // Turn the Bit Off
 
         if( writeCV( CVAddr, tempValue ) == tempValue )
-          ackFunction() ;
+          ackAdvancedCV() ;
       }
     }
 
@@ -924,12 +776,12 @@ void processDirectCVOperation( uint8_t Cmd, uint16_t CVAddr, uint8_t Value, void
         if( BitValue ) 
         {
           if( tempValue & BitMask )
-            ackFunction() ;
+            ackAdvancedCV() ;
         }
         else
         {
           if( !( tempValue & BitMask)  )
-            ackFunction() ;
+            ackAdvancedCV() ;
         }
       }
     }
@@ -972,8 +824,9 @@ void processMultiFunctionMessage( uint16_t Addr, DCC_ADDR_TYPE AddrType, uint8_t
     switch( Cmd & 0b00001110 )
     {
     case 0b00000000:  
+      if( notifyDccReset && ( Cmd & 0b00000001 ) ) // Hard Reset
         if( notifyDccReset)
-        notifyDccReset( Cmd & 0b00000001 ) ;
+          notifyDccReset( 1 ) ;
       break ;
 
     case 0b00000010:  // Factory Test
@@ -1106,7 +959,7 @@ void processMultiFunctionMessage( uint16_t Addr, DCC_ADDR_TYPE AddrType, uint8_t
   case 0b11100000:  // CV Access
     CVAddr = ( ( ( Cmd & 0x03 ) << 8 ) | Data1 ) + 1 ;
 
-    processDirectCVOperation( Cmd, CVAddr, Data2, ackAdvancedCV) ;
+    processDirectOpsOperation( Cmd, CVAddr, Data2 ) ;
     break;
   }
 }
@@ -1121,7 +974,7 @@ void processServiceModeOperation( DCC_MSG * pDccMsg )
   if( pDccMsg->Size == 3) // 3 Byte Packets are for Address Only, Register and Paged Mode
   {
     uint8_t RegisterAddr ;
-    DB_PRINT("CV Address, Register & Paged Mode Operation");
+    DB_PRINT("3-BytePkt");
     RegisterAddr = pDccMsg->Data[0] & 0x07 ;
     Value = pDccMsg->Data[1] ;
 
@@ -1164,11 +1017,11 @@ void processServiceModeOperation( DCC_MSG * pDccMsg )
 
   else if( pDccMsg->Size == 4) // 4 Byte Packets are for Direct Byte & Bit Mode
   {
-    DB_PRINT("CV Direct Byte and Bit Mode Mode Operation");
+    DB_PRINT("BB-Mode");
     CVAddr = ( ( ( pDccMsg->Data[0] & 0x03 ) << 8 ) | pDccMsg->Data[1] ) + 1 ;
     Value = pDccMsg->Data[2] ;
 
-    processDirectCVOperation( pDccMsg->Data[0] & 0b00001100, CVAddr, Value, ackCV) ;
+    processDirectOpsOperation( pDccMsg->Data[0] & 0b00001100, CVAddr, Value ) ;
   }
 }
 #endif
@@ -1245,13 +1098,12 @@ void execDccProcessor( DCC_MSG * pDccMsg )
     {
       resetServiceModeTimer( 1 ) ;
 
-	//Only check the DCC Packet "Size" and "Data" fields and ignore the "PreambleBits" as they can be different to the previous packet
-      if(pDccMsg->Size != DccProcState.LastMsg.Size || memcmp( pDccMsg->Data, &DccProcState.LastMsg.Data, pDccMsg->Size ) != 0 )	      
+      if( memcmp( pDccMsg, &DccProcState.LastMsg, sizeof( DCC_MSG ) ) )
       {
         DccProcState.DuplicateCount = 0 ;
         memcpy( &DccProcState.LastMsg, pDccMsg, sizeof( DCC_MSG ) ) ;
       }
-      // Wait until you see 2 identical packets before acting on a Service Mode Packet 
+      // Wait until you see 2 identicle packets before acting on a Service Mode Packet 
       else
       {
         DccProcState.DuplicateCount++ ;
@@ -1522,15 +1374,10 @@ void NmraDcc::pin( uint8_t ExtIntNum, uint8_t ExtIntPinNum, uint8_t EnablePullup
   DccProcState.ExtIntNum = ExtIntNum;
 #endif
   DccProcState.ExtIntPinNum = ExtIntPinNum;
-#ifdef __AVR_MEGA__
-    // because digitalRead at AVR is slow, we will read the dcc input in the ISR
-    // by direct port access.
-    DccProcState.ExtIntPort = portInputRegister( digitalPinToPort(ExtIntPinNum) );
-    DccProcState.ExtIntMask = digitalPinToBitMask( ExtIntPinNum );
-#else
-    DccProcState.ExtIntMask = 1;
-#endif	
-  pinMode( ExtIntPinNum, EnablePullup ? INPUT_PULLUP : INPUT );
+	
+  pinMode( ExtIntPinNum, INPUT );
+  if( EnablePullup )
+    digitalWrite(ExtIntPinNum, HIGH);
 }
 
 ////////////////////////////////////////////////////////////////////////
@@ -1564,9 +1411,6 @@ void NmraDcc::init( uint8_t ManufacturerId, uint8_t VersionId, uint8_t Flags, ui
   DccProcState.inAccDecDCCAddrNextReceivedMode = 0;
 
   ISREdge = RISING;
-  // level checking to detect false IRQ's fired by glitches
-  ISRLevel = DccProcState.ExtIntMask;
-  ISRChkMask = DccProcState.ExtIntMask;
 
   #ifdef ESP32
   ISRWatch = ISREdge;
@@ -1677,6 +1521,7 @@ uint8_t NmraDcc::process()
   if( DccRx.DataReady )
   {
     // We need to do this check with interrupts disabled
+    //SET_TP4;
 #ifdef ESP32
     portENTER_CRITICAL(&mux);
 #else
@@ -1690,16 +1535,25 @@ uint8_t NmraDcc::process()
 #else
     interrupts();
 #endif
-    // Checking of the XOR-byte is now done in the ISR already
       #ifdef DCC_DBGVAR
       countOf.Tel++;
       #endif
-    // Clear trailing bytes
-    for ( byte i=Msg.Size; i< MAX_DCC_MESSAGE_LEN; i++ ) Msg.Data[i] = 0;
     
+    uint8_t xorValue = 0 ;
+    
+    for(uint8_t i = 0; i < DccRx.PacketCopy.Size; i++)
+      xorValue ^= DccRx.PacketCopy.Data[i];
+    if(xorValue) {
+      #ifdef DCC_DBGVAR
+      DB_PRINT("Cerr");
+      countOf.Err++;
+      #endif
+      return 0 ;
+    } else {
 		if( notifyDccMsg ) 	notifyDccMsg( &Msg );
 		
         execDccProcessor( &Msg );
+    }
     return 1 ;
   }
 

NmraDcc.h

@@ -2,21 +2,11 @@
 //
 // Model Railroading with Arduino - NmraDcc.h 
 //
-// Copyright (c) 2008 - 2020 Alex Shepherd
+// Copyright (c) 2008 - 2018 Alex Shepherd
 //
-// 	This library is free software; you can redistribute it and/or
-// 	modify it under the terms of the GNU Lesser General Public
-// 	License as published by the Free Software Foundation; either
-// 	version 2.1 of the License, or (at your option) any later version.
-// 
-// 	This library is distributed in the hope that it will be useful,
-// 	but WITHOUT ANY WARRANTY; without even the implied warranty of
-// 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// 	Lesser General Public License for more details.
-// 
-// 	You should have received a copy of the GNU Lesser General Public
-// 	License along with this library; if not, write to the Free Software
-// 	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+// This source file is subject of the GNU general public license 2,
+// that is available at the world-wide-web at
+// http://www.gnu.org/licenses/gpl.txt
 // 
 //------------------------------------------------------------------------
 //
@@ -54,10 +44,12 @@
 #include "WProgram.h"
 #endif
 
+#include "EEPROM.h"
+
 #ifndef NMRADCC_IS_IN
 #define NMRADCC_IS_IN
 
-#define NMRADCC_VERSION     206     // Version 2.0.6
+#define NMRADCC_VERSION     201     // Version 2.0.1
 
 #define MAX_DCC_MESSAGE_LEN 6    // including XOR-Byte
 
@@ -126,7 +118,7 @@ typedef enum {
     CV29_LOCO_DIR            = 0b00000001,	/** bit 0: Locomotive Direction: "0" = normal, "1" = reversed */
     CV29_F0_LOCATION         = 0b00000010,	/** bit 1: F0 location: "0" = bit 4 in Speed and Direction instructions, "1" = bit 4 in function group one instruction */
     CV29_APS                 = 0b00000100,	/** bit 2: Alternate Power Source (APS) "0" = NMRA Digital only, "1" = Alternate power source set by CV12 */
-	CV29_RAILCOM_ENABLE      = 0b00001000, 	/** bit 3: BiDi ( RailCom ) is active */
+    CV29_ADV_ACK             = 0b00001000, 	/** bit 3: ACK, Advanced Acknowledge mode enabled if 1, disabled if 0 */
     CV29_SPEED_TABLE_ENABLE  = 0b00010000, 	/** bit 4: STE, Speed Table Enable, "0" = values in CVs 2, 4 and 6, "1" = Custom table selected by CV 25 */
     CV29_EXT_ADDRESSING      = 0b00100000,	/** bit 5: "0" = one byte addressing, "1" = two byte addressing */
     CV29_OUTPUT_ADDRESS_MODE = 0b01000000,	/** bit 6: "0" = Decoder Address Mode "1" = Output Address Mode */
@@ -712,8 +704,9 @@ extern void    notifyCVResetFactoryDefault(void) __attribute__ ((weak));
  */
 extern void    notifyCVAck(void) __attribute__ ((weak));
 /*+
- *  notifyAdvancedCVAck() Called when a CV write must be acknowledged via Advanced Acknowledgement.
- *                This callback must send the Advanced Acknowledgement via RailComm.
+ *  notifyAdvancedCVAck() Called when a CV write must be acknowledged.
+ *                This callback must increase the current drawn by this
+ *                decoder by at least 60mA for 6ms +/- 1ms.
  *
  *  Inputs:
  *    None

examples/DCCInterface_TurntableControl/DCCInterface_TurntableControl.ino

@@ -1,8 +1,8 @@
 // DCC Stepper Motor Controller ( A4988 ) Example for Model Railroad Turntable Control
 //
-// See: https://www.dccinterface.com/product/arduino-model-railway-dcc-stepper-motor-controller-a4988-assembled/
+// See: https://www.dccinterface.com/how-to/assemblyguide/
 // 
-// Author: Alex Shepherd 2020-06-01
+// Author: Alex Shepherd 2017-12-04
 // 
 // This example requires two Arduino Libraries:
 //
@@ -22,18 +22,8 @@
 // The lines below define the pins used to connect to the A4988 driver module
 #define A4988_STEP_PIN      4
 #define A4988_DIRECTION_PIN 5
-#define A4988_ENABLE_PIN    6
-
-#ifdef A4988_ENABLE_PIN
 // Uncomment the next line to enable Powering-Off the Stepper when its not running to reduce heating the motor and driver
-#define DISABLE_OUTPUTS_IDLE
-#endif
-
-// By default the stepper motor will move the shortest distance to the desired position.
-// If you need the turntable to only move in the Positive/Increasing or Negative/Decreasing step numbers to better handle backlash in the mechanism
-// Then uncomment the appropriate line below
-//#define ALWAYS_MOVE_POSITIVE
-//#define ALWAYS_MOVE_NEGATIVE
+#define A4988_ENABLE_PIN    6
 
 // The lines below define the stepping speed and acceleration, which you may need to tune for your application
 #define STEPPER_MAX_SPEED     800   // Sets the maximum permitted speed
@@ -102,9 +92,6 @@ TurnoutPosition turnoutPositions[] = {
 // --------------------------------------------------------------------------------------------
 // You shouldn't need to edit anything below this line unless you're needing to make big changes... ;)
 // --------------------------------------------------------------------------------------------
-#if defined(ALWAYS_MOVE_POSITIVE) && defined(ALWAYS_MOVE_NEGATIVE)
-#error ONLY uncomment one of ALWAYS_MOVE_POSITIVE or ALWAYS_MOVE_NEGATIVE but NOT both
-#endif
 
 #define MAX_TURNOUT_POSITIONS (sizeof(turnoutPositions) / sizeof(TurnoutPosition))
 
@@ -117,12 +104,11 @@ NmraDcc  Dcc ;
 // Variables to store the last DCC Turnout message Address and Direction  
 uint16_t lastAddr = 0xFFFF ;
 uint8_t lastDirection = 0xFF;
-int     lastStep = 0;
 
 // This function is called whenever a normal DCC Turnout Packet is received
 void notifyDccAccTurnoutOutput( uint16_t Addr, uint8_t Direction, uint8_t OutputPower )
 {
-  Serial.print(F("notifyDccAccTurnoutOutput: "));
+  Serial.print("notifyDccAccTurnoutOutput: ") ;
   Serial.print(Addr,DEC) ;
   Serial.print(',');
   Serial.print(Direction,DEC) ;
@@ -145,50 +131,23 @@ void notifyDccAccTurnoutOutput( uint16_t Addr, uint8_t Direction, uint8_t Output
 #ifdef A4988_ENABLE_PIN
       stepper1.enableOutputs();
 #endif
-
-      int newStep;
-      if(Direction)
-        newStep = turnoutPositions[i].positionFront;
-      else
-        newStep = turnoutPositions[i].positionBack;
-
-      Serial.print(newStep, DEC);
-      
-      Serial.print(F("  Last Step: "));
-      Serial.print(lastStep, DEC);
-      
-      int diffStep = newStep - lastStep;
-      Serial.print(F("  Diff Step: "));
-      Serial.print(diffStep, DEC);
-
-#if defined ALWAYS_MOVE_POSITIVE
-      Serial.print(F("  Positive"));       
-      if(diffStep < 0)
-        diffStep += FULL_TURN_STEPS;
-        
-#elif defined ALWAYS_MOVE_NEGATIVE
-      Serial.print(F("  Negative"));       
-      if(diffStep > 0)
-        diffStep -= FULL_TURN_STEPS;
-#else
-      if(diffStep > HALF_TURN_STEPS)
-        diffStep = diffStep - FULL_TURN_STEPS;
-        
-      else if(diffStep < -HALF_TURN_STEPS)
-        diffStep = diffStep + FULL_TURN_STEPS;
-#endif
-
-      Serial.print(F("  Move: "));
-      Serial.println(diffStep, DEC);
-      stepper1.move(diffStep);
-
-      lastStep = newStep;
+      if (Direction)
+      {
+        Serial.println(turnoutPositions[i].positionFront, DEC);
+        stepper1.moveTo(turnoutPositions[i].positionFront);
         break;
       }
+      else
+      {
+        Serial.println(turnoutPositions[i].positionBack, DEC);
+        stepper1.moveTo(turnoutPositions[i].positionBack);
+        break;
+      }
+    }
   }
 };
 
-#ifdef DISABLE_OUTPUTS_IDLE
+#ifdef A4988_ENABLE_PIN
 bool lastIsRunningState ;
 #endif 
 
@@ -204,10 +163,6 @@ void setupStepperDriver()
   stepper1.setSpeed(STEPPER_SPEED);               // Sets the desired constant speed for use with runSpeed()
  
 #ifdef A4988_ENABLE_PIN
-  stepper1.enableOutputs();
-#endif
-
-#ifdef DISABLE_OUTPUTS_IDLE
   lastIsRunningState = stepper1.isRunning();
 #endif
 }
@@ -218,19 +173,14 @@ bool moveToHomePosition()
 
   pinMode(HOME_SENSOR_PIN, INPUT_PULLUP);
 
-#ifdef ALWAYS_MOVE_NEGATIVE
-  stepper1.move(0 - (FULL_TURN_STEPS * 2));
-#else
   stepper1.move(FULL_TURN_STEPS * 2);
-#endif  
   while(digitalRead(HOME_SENSOR_PIN) != HOME_SENSOR_ACTIVE_STATE)
     stepper1.run();
 
   if(digitalRead(HOME_SENSOR_PIN) == HOME_SENSOR_ACTIVE_STATE)
   {
-    stepper1.stop();
-    stepper1.setCurrentPosition(0);
     Serial.println(F("Found Home Position - Setting Current Position to 0"));
+    stepper1.setCurrentPosition(0);
     return true;
   }
   else
@@ -260,32 +210,28 @@ void setup()
   Serial.print(F("Full Rotation Steps: "));
   Serial.println(FULL_TURN_STEPS);
 
-  Serial.print(F("Movement Strategy: "));
-#if defined ALWAYS_MOVE_POSITIVE
-  Serial.println(F("Positive Direction Only"));
-#elif defined ALWAYS_MOVE_NEGATIVE
-  Serial.println(F("Negative Direction Only"));
-#else
-  Serial.println(F("Shortest Distance"));
-#endif
-
   for(uint8_t i = 0; i < MAX_TURNOUT_POSITIONS; i++)
   {
-    Serial.print(F("DCC Addr: "));
+    Serial.print("DCC Addr: ");
     Serial.print(turnoutPositions[i].dccAddress);
 
-    Serial.print(F(" Front: "));
+    Serial.print(" Front: ");
     Serial.print(turnoutPositions[i].positionFront);
 
-    Serial.print(F(" Back: "));
+    Serial.print(" Back: ");
     Serial.println(turnoutPositions[i].positionBack);
   }
   
   setupStepperDriver();
+
   if(moveToHomePosition());
   { 
     setupDCCDecoder();
 
+  #ifdef A4988_ENABLE_PIN
+    stepper1.enableOutputs();
+  #endif
+
     // Fake a DCC Packet to cause the Turntable to move to Position 1
     notifyDccAccTurnoutOutput(POSITION_01_DCC_ADDRESS, 1, 1);
   }
@@ -299,7 +245,7 @@ void loop()
   // Process the Stepper Library
   stepper1.run();
 
-#ifdef DISABLE_OUTPUTS_IDLE
+#ifdef A4988_ENABLE_PIN
   if(stepper1.isRunning() != lastIsRunningState)
   {
     lastIsRunningState = stepper1.isRunning();

library.properties

@@ -1,5 +1,5 @@
 name=NmraDcc
-version=2.0.6
+version=2.0.2
 author=Alex Shepherd, Wolfgang Kuffer, Geoff Bunza, Martin Pischky, Franz-Peter Müller, Sven (littleyoda), Hans Tanner
 maintainer=Alex Shepherd <kiwi64ajs@gmail.com>
 sentence=Enables NMRA DCC Communication