Added auto-configure for Uno/Mega as well as Motor Shield Type

* board type detected at compile-time
* macro to select type of motor shield (Arduino or Pololu MC32926
* new <e> command that clears EEPROM
* safety check added to reject throttle command with nReg out-of-bounds
(<1 or >MaxNumRegs)

DCCpp_Uno/Accessories.cpp

@@ -40,7 +40,7 @@ where
 
 Once all turnouts have been properly defined, use the <E> command to store their definitions to EEPROM.
 If you later make edits/additions/deletions to the turnout definitions, you must invoke the <E> command if you want those
-new definitions updated in the EEPROM.
+new definitions updated in the EEPROM.  You can also clear everything stored in the EEPROM by invoking the <e> command.
 
 To "throw" turnouts that have been defined use:
 

DCCpp_Uno/DCCpp_Uno.h

@@ -10,31 +10,68 @@ Part of DCC++ BASE STATION for the Arduino Uno
 #ifndef DCCpp_Uno_h
 #define DCCpp_Uno_h
 
-#define  BASE_STATION_VERSION  "UNO_1.0"
+#if defined  ARDUINO_AVR_UNO
+#define ARDUINO_TYPE    "UNO"
 
-// Define the Arduino Pins that control various functions
+#define DCC_SIGNAL_PIN_MAIN 10          // Ardunio Uno
+#define DCC_SIGNAL_PIN_PROG 5           // Arduino Uno
+
+#elif defined  ARDUINO_AVR_MEGA2560
+#define ARDUINO_TYPE    "MEGA"
+
+#define DCC_SIGNAL_PIN_MAIN 12          // Arduino Mega
+#define DCC_SIGNAL_PIN_PROG 4           // Arduino Mega
+
+#else
+
+#error CAN'T COMPILE - DCC++ ONLY WORKS WITH AN ARDUINO UNO OR AN ARDUINO MEGA 2560
+#endif
+
+/////////////////////////////////////////////////////////////////////////////////////
+//
+// DEFINE MOTOR SHIELD PINS - SET MOTOR_SHIELD_TYPE ACCORDING TO THE FOLLOWING TABLE:
+//
+//  0 = ARDUINO MOTOR SHIELD          (MAX 18V/2A PER CHANNEL)
+//  1 = POLOLU MC33926 MOTOR SHIELD   (MAX 28V/3A PER CHANNEL)
+
+#define MOTOR_SHIELD_TYPE   0
+
+/////////////////////////////////////////////////////////////////////////////////////
+
+#if MOTOR_SHIELD_TYPE == 0
+
+#define MOTOR_SHIELD_NAME "ARDUINO MOTOR SHIELD"
 
 #define SIGNAL_ENABLE_PIN_MAIN 3
 #define SIGNAL_ENABLE_PIN_PROG 11
 
 #define CURRENT_MONITOR_PIN_MAIN A0
 #define CURRENT_MONITOR_PIN_PROG A1
 
-#define DCC_SIGNAL_PIN_MAIN 10          // Ardunio Uno
-#define DCC_SIGNAL_PIN_PROG 5           // Arduino Uno
-
 #define DIRECTION_MOTOR_CHANNEL_PIN_A 12
 #define DIRECTION_MOTOR_CHANNEL_PIN_B 13
 
-// Define number of MAIN TRACK Registers
+#elif MOTOR_SHIELD_TYPE == 1
 
-#define MAX_MAIN_REGISTERS 12
+#define MOTOR_SHIELD_NAME "POLOLU MC33926 MOTOR SHIELD"
+
+#define SIGNAL_ENABLE_PIN_MAIN 9
+#define SIGNAL_ENABLE_PIN_PROG 11
+
+#define CURRENT_MONITOR_PIN_MAIN A0
+#define CURRENT_MONITOR_PIN_PROG A1
 
-enum { EE_NTURNOUTS, EE_NSENSORS };
+#define DIRECTION_MOTOR_CHANNEL_PIN_A 7
+#define DIRECTION_MOTOR_CHANNEL_PIN_B 8
 
-// Define slots for EE_PROM storage of key variables.  EE_TURNOUT must be last since it is starting point for a number of turnouts
+#else
+
+#error CAN'T COMPILE - PLEASE SELECT A PROPER MOTOR SHIELD TYPE
+#endif
 
-enum { EE_TURNOUT };
+// Define number of MAIN TRACK Registers
+
+#define MAX_MAIN_REGISTERS 12
 
 // If SHOW_PACKETS is set to 1, then for select main operations track commands that modify an internal DCC packet register,
 // if printFlag for that command is also set to 1, DCC++ BASE STATION will additionally return the 

DCCpp_Uno/EEStore.cpp

@@ -36,6 +36,17 @@ void EEStore::init(){
 
 ///////////////////////////////////////////////////////////////////////////////
 
+void EEStore::clear(){
+
+  sprintf(eeStore->data.id,EESTORE_ID);                           // create blank eeStore structure (no turnouts, no sensors) and save it back to EEPROM
+  eeStore->data.nTurnouts=0;
+  eeStore->data.nSensors=0;
+  EEPROM.put(0,eeStore->data);    
+
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
 void EEStore::store(){
   reset();
   Turnout::store();

DCCpp_Uno/EEStore.h

@@ -27,6 +27,7 @@ struct EEStore{
   static int pointer();
   static void advance(int);
   static void store();
+  static void clear();
 };
 
 #endif

DCCpp_Uno/PacketRegister.cpp

@@ -108,6 +108,9 @@ void RegisterList::setThrottle(char *s) volatile{
   if(sscanf(s,"%d %d %d %d",&nReg,&cab,&tSpeed,&tDirection)!=4)
     return;
 
+  if(nReg<1 || nReg>maxNumRegs)
+    return;  
+
   if(cab>127)
     b[nB++]=highByte(cab) | 0xC0;      // convert train number into a two-byte address
 

DCCpp_Uno/Sensor.cpp

@@ -42,7 +42,7 @@ where
 
 Once all sensors have been properly defined, use the <E> command to store their definitions to EEPROM.
 If you later make edits/additions/deletions to the sensor definitions, you must invoke the <E> command if you want those
-new definitions updated in the EEPROM.
+new definitions updated in the EEPROM.  You can also clear everything stored in the EEPROM by invoking the <e> command.
 
 All sensors defined as per above are repeatedly and sequentially checked within the main loop of this sketch.
 If a Sensor Pin is found to have transitioned from one state to another, one of the following serial messages are generated:

DCCpp_Uno/SerialCommand.cpp

@@ -318,8 +318,10 @@ void SerialCommand::parse(char *com){
           Serial.print(" 0>");
         }          
       }
-      Serial.print("<iDCC++ BASE STATION v");
-      Serial.print(BASE_STATION_VERSION);
+      Serial.print("<iDCC++ BASE STATION FOR ARDUINO ");
+      Serial.print(ARDUINO_TYPE);
+      Serial.print(" / ");
+      Serial.print(MOTOR_SHIELD_NAME);
       Serial.print(": BUILD ");
       Serial.print(__DATE__);
       Serial.print(" ");
@@ -334,7 +336,7 @@ void SerialCommand::parse(char *com){
 
     case 'E':     // <E>
 /*
- *    stores settings for Turnouts in EEPROM
+ *    stores settings for turnouts and sensors EEPROM
  *    
  *    returns: <e nTurnouts nSensors>
 */
@@ -347,6 +349,19 @@ void SerialCommand::parse(char *com){
     Serial.print(">");
     break;
 
+/***** CLEAR SETTINGS IN EEPROM  ****/    
+
+    case 'e':     // <e>
+/*
+ *    clears settings for Turnouts in EEPROM
+ *    
+ *    returns: <O>
+*/
+
+    EEStore::clear();
+    Serial.print("<O>");
+    break;
+
 /***** PRINT CARRIAGE RETURN IN SERIAL MONITOR WINDOW  ****/    
 
     case ' ':     // < >