Removed ISR overtaken message from ISR routine

Marlin/Marlin.pde

   manage_heater();
   manage_inactivity(1);
   checkHitEndstops();
+  checkStepperErrors();
   LCD_STATUS;
 }
 

Marlin/stepper.cpp

 static bool old_z_min_endstop=false;
 static bool old_z_max_endstop=false;
 
+static bool bussy_error=false;
+unsigned char OCR1A_error=12345;
+
 volatile long count_position[NUM_AXIS] = { 0, 0, 0, 0};
 volatile char count_direction[NUM_AXIS] = { 1, 1, 1, 1};
 
 #define ENABLE_STEPPER_DRIVER_INTERRUPT()  TIMSK1 |= (1<<OCIE1A)
 #define DISABLE_STEPPER_DRIVER_INTERRUPT() TIMSK1 &= ~(1<<OCIE1A)
 
+void checkStepperErrors()
+{
+  if(bussy_error) {
+    SERIAL_ERROR_START
+    SERIAL_ERROR(OCR1A_error);
+    SERIAL_ERRORLNPGM(" ISR overtaking itself.");
+    bussy_error = false;
+  }
+}
+
 void checkHitEndstops()
 {
  if( endstop_x_hit || endstop_y_hit || endstop_z_hit) {
 ISR(TIMER1_COMPA_vect)
 {        
   if(busy){ 
-    SERIAL_ERROR_START
-    SERIAL_ERROR(*(unsigned short *)OCR1A);
-    SERIAL_ERRORLNPGM(" ISR overtaking itself.");
+    OCR1A_error = OCR1A;
+    bussy_error = true;
     OCR1A = 0x30000;
     return; 
   } // The busy-flag is used to avoid reentering this interrupt

Marlin/stepper.h

 void checkHitEndstops(); //call from somwhere to create an serial error message with the locations the endstops where hit, in case they were triggered
 void endstops_hit_on_purpose(); //avoid creation of the message, i.e. after homeing and before a routine call of checkHitEndstops();
 
-
+void checkStepperErrors(); //Print errors detected by the stepper
 
 extern block_t *current_block;  // A pointer to the block currently being traced