Merge branch 'master' into MicroBahner-Without-use-of-HW-timers

* master:
  Fixed issue reported by lucari Despite the values set for F0-4, a packet with all fields set to zero is received. The problem seems to be related to NrmaDcc.cpp and a hidden 'break' statement at line 484. This should be swapped with the #endif on the next line. The result is that when a Speed packet is processed, it drops through to the next case statement and sends an empty DCCFunc command.
  Added Iowa Scaled Engineering ARD-DCCSHIELD example
  fixed call-back function void notifyDccFunc and changed version to 1.2.1

NmraDcc.cpp

@@ -683,8 +683,8 @@ void processMultiFunctionMessage( uint16_t Addr, DCC_ADDR_TYPE AddrType, uint8_t
       uint8_t fn0 = (Cmd & 0b00010000) ;
       notifyDccFunc( Addr, AddrType, FN_0, fn0 ) ;
     }
-    break;
 #endif
+    break;
 
   case 0b10000000:  // Function Group 0..4
     if( notifyDccFunc )

examples/NmraDcc_ARD_DCCSHIELD/NmraDcc_ARD_DCCSHIELD.ino

@@ -0,0 +1,123 @@
+#include <NmraDcc.h>
+
+// This Example shows how to use the library with the Iowa Scaled Engineering ARD-DCCSHIELD
+// You can find out more about this DCC Interface here: http://www.iascaled.com/store/ARD-DCCSHIELD
+//
+// For more information refer to the file: README.md here: https://github.com/IowaScaledEngineering/ard-dccshield
+//
+// This demo assumes the following Jumper settings on the ARD-DCCSHIELD
+//
+// JP1 - I2C Pull-Up Resistors                        - Don't Care
+// JP2 - (Pins 1-2) I2C /IORST JP2                    - Don't-Care
+// JP2 - (Pins 3-4) - DCC Signal to Arduino Pin       - OFF
+// JP3 - I2C /INT and /OE                             - Don't-Care
+// JP4 - DCC Signal to Arduino Pin                    - D2 ON
+// JP5 - Arduino Powered from DCC                     - User Choice
+// JP6 - Boards without VIO                           - User Choice
+// JP7 - Enable Programming ACK                       - 1-2 ON 3-4 ON 
+// 
+// It is a very basic DCC Accessory Decoder that does nothing except allow CV Read/Write and 
+// you can also print every DCC packet by uncommenting the "#define NOTIFY_DCC_MSG" line below
+#define NOTIFY_DCC_MSG
+
+// You can also print other Debug Messages uncommenting the line below
+#define DEBUG_MSG
+
+// Un-Comment the line below to Enable DCC ACK for Service Mode Programming Read CV Capablilty 
+#define ENABLE_DCC_ACK  15  // This is A1 on the Iowa Scaled Engineering ARD-DCCSHIELD DCC Shield
+
+NmraDcc  Dcc ;
+
+struct CVPair
+{
+  uint16_t  CV;
+  uint8_t   Value;
+};
+
+CVPair FactoryDefaultCVs [] =
+{
+  {CV_ACCESSORY_DECODER_ADDRESS_LSB, 1},
+  {CV_ACCESSORY_DECODER_ADDRESS_MSB, 0},
+};
+
+uint8_t FactoryDefaultCVIndex = 0;
+
+void notifyCVResetFactoryDefault()
+{
+#ifdef DEBUG_MSG
+  Serial.println("notifyCVResetFactoryDefault: Settings CVs to Factory Defaults") ;
+#endif  // Make FactoryDefaultCVIndex non-zero and equal to num CV's to be reset 
+  // to flag to the loop() function that a reset to Factory Defaults needs to be done
+  FactoryDefaultCVIndex = sizeof(FactoryDefaultCVs)/sizeof(CVPair);
+};
+
+// This function is called by the NmraDcc library when a DCC ACK needs to be sent
+// Calling this function should cause an increased 60ma current drain on the power supply for 6ms to ACK a CV Read 
+#ifdef  ENABLE_DCC_ACK
+void notifyCVAck(void)
+{
+#ifdef DEBUG_MSG
+  Serial.println("notifyCVAck") ;
+#endif
+  // Configure the DCC CV Programing ACK pin for an output
+  pinMode( ENABLE_DCC_ACK, OUTPUT );
+
+  // Generate the DCC ACK 60mA pulse
+  digitalWrite( ENABLE_DCC_ACK, HIGH );
+  delay( 10 );  // The DCC Spec says 6ms but 10 makes sure... ;)
+  digitalWrite( ENABLE_DCC_ACK, LOW );
+}
+#endif
+
+#ifdef  NOTIFY_DCC_MSG
+void notifyDccMsg( DCC_MSG * Msg)
+{
+  Serial.print("notifyDccMsg: ") ;
+  for(uint8_t i = 0; i < Msg->Size; i++)
+  {
+    Serial.print(Msg->Data[i], HEX);
+    Serial.write(' ');
+  }
+  Serial.println();
+}
+#endif
+
+void notifyCVChange(uint16_t CV, uint8_t Value)
+{
+#ifdef DEBUG_MSG
+  Serial.print("notifyCVChange: CV: ") ;
+  Serial.print(CV,DEC) ;
+  Serial.print(" Value: ") ;
+  Serial.println(Value, DEC) ;
+#else
+  Value = Value;  // Silence Compiler Warnings...
+  CV = CV;
+#endif  
+}
+
+void setup()
+{
+  Serial.begin(115200);
+  
+  Serial.println("NMRA DCC Iowa Scaled Engineering ARD-DCCSHIELD Example");
+  
+  // Setup which External Interrupt, the Pin it's associated with that we're using and enable the Pull-Up 
+  Dcc.pin(0, 2, 1);
+  
+  // Call the main DCC Init function to enable the DCC Receiver
+  Dcc.init( MAN_ID_DIY, 10, CV29_ACCESSORY_DECODER, 0 );
+
+  Serial.println("Init Done");
+}
+
+void loop()
+{
+  // You MUST call the NmraDcc.process() method frequently from the Arduino loop() function for correct library operation
+  Dcc.process();
+  
+  if( FactoryDefaultCVIndex && Dcc.isSetCVReady())
+  {
+    FactoryDefaultCVIndex--; // Decrement first as initially it is the size of the array 
+    Dcc.setCV( FactoryDefaultCVs[FactoryDefaultCVIndex].CV, FactoryDefaultCVs[FactoryDefaultCVIndex].Value);
+  }
+}