First cleanup. Moved all code to cpp files, so there are no dependencies on pde files. And no more odd requirement to cat files together. (Still need to fix the Makefile). Also cleaned up some defines and made defines upper case as by C coding conventions.

Marlin/watchdog.cpp

@@ -0,0 +1,54 @@
+#include "Marlin.h"
+
+#ifdef USE_WATCHDOG
+#include "watchdog.h"
+#include "ultralcd.h"
+
+//===========================================================================
+//=============================private variables  ============================
+//===========================================================================
+
+//===========================================================================
+//=============================functinos         ============================
+//===========================================================================
+
+
+/// intialise watch dog with a 1 sec interrupt time
+void watchdog_init()
+{
+#ifdef RESET_MANUAL
+    //We enable the watchdog timer, but only for the interrupt.
+    //Take care, as this requires the correct order of operation, with interrupts disabled. See the datasheet of any AVR chip for details.
+    wdt_reset();
+    _WD_CONTROL_REG = _BV(_WD_CHANGE_BIT) | _BV(WDE);
+    _WD_CONTROL_REG = _BV(WDIE) | WDTO_1S;
+#else
+    wdt_enable(WDTO_1S);
+#endif
+}
+
+/// reset watchdog. MUST be called every 1s after init or avr will reset.
+void watchdog_reset() 
+{
+  wdt_reset();
+}
+
+//===========================================================================
+//=============================ISR               ============================
+//===========================================================================
+
+//Watchdog timer interrupt, called if main program blocks >1sec and manual reset is enabled.
+#ifdef RESET_MANUAL
+ISR(WDT_vect)
+{ 
+    LCD_MESSAGEPGM("ERR:Please Reset");//16 characters so it fits on a 16x2 display
+    LCD_STATUS;
+    SERIAL_ERROR_START;
+    SERIAL_ERRORLNPGM("Something is wrong, please turn off the printer.");
+
+    kill(); //kill blocks
+    while(1); //wait for user or serial reset
+}
+#endif//RESET_MANUAL
+
+#endif//USE_WATCHDOG