Fixed bug in short-circuit detection for MEGA

The short-circuit code polled the track current every 10 “milliseconds.” But Arduino millis() is based on TIMER-0 settings which are changed in DCC++ Base Station. The actual polling was closer to every 1 millisecond. When Base Station for the Mega for updated to utilize TIMER-3 instead of TIMER-0, the millis() function now really did count milliseconds, and 10 milliseconds between each track-current sampling was too long. Changed the code so that for the Mega, the current sampling time is defined as 1 (instead of 10), representing an actual 1 millisecond as desired.

Author: DccPlusPlus

DCCpp_Uno/CurrentMonitor.cpp

@@ -22,7 +22,7 @@ CurrentMonitor::CurrentMonitor(int pin, char *msg){
 boolean CurrentMonitor::checkTime(){
  if(millis()-sampleTime<CURRENT_SAMPLE_TIME) // no need to check current yet
  return(false);
- sampleTime=millis();
+ sampleTime=millis(); // note millis() uses TIMER-0. For UNO, we change the scale on Timer-0. For MEGA we do not. This means CURENT_SAMPLE_TIME is different for UNO then MEGA
  return(true); 
 } // CurrentMonitor::checkTime
 

DCCpp_Uno/CurrentMonitor.h

@@ -13,9 +13,14 @@ Part of DCC++ BASE STATION for the Arduino
 #include "Arduino.h"
 
 #define CURRENT_SAMPLE_SMOOTHING 0.01
-#define CURRENT_SAMPLE_TIME 10
 #define CURRENT_SAMPLE_MAX 300
 
+#ifdef ARDUINO_AVR_UNO // Configuration for UNO
+ #define CURRENT_SAMPLE_TIME 10
+#else // Configuration for MEGA 
+ #define CURRENT_SAMPLE_TIME 1
+#endif
+
 struct CurrentMonitor{
  static long int sampleTime;
  int pin;