diff --git a/scheduler.h b/scheduler.h
index aa4816e..4ccff37 100644
--- a/scheduler.h
+++ b/scheduler.h
@@ -35,8 +35,8 @@ void setIgnitionSchedule2(void (*startCallback)(), unsigned long timeout, unsign
 enum ScheduleStatus {OFF, PENDING, RUNNING}; //The 3 statuses that a schedule can have
 
 struct Schedule {
-  unsigned long duration;
-  ScheduleStatus Status;
+  volatile unsigned long duration;
+  volatile ScheduleStatus Status;
   void (*StartCallback)(); //Start Callback function for schedule
   void (*EndCallback)(); //Start Callback function for schedule
 };
diff --git a/scheduler.ino b/scheduler.ino
index dd096fa..0c66744 100644
--- a/scheduler.ino
+++ b/scheduler.ino
@@ -91,10 +91,13 @@ void setIgnitionSchedule2(void (*startCallback)(), unsigned long timeout, unsign
     TIMSK5 |= (1 << OCIE5B); //Turn on the A compare unit (ie turn on the interrupt)
   }
   
-//Timer3A (fuel schedule 1) Compare Vector
-//This function gets called when either the start time or the duration time are reached
+  
+  
+
+//This function (All 4 ISR functions that are below) gets called when either the start time or the duration time are reached
 //This calls the relevant callback function (startCallback or endCallback) depending on the status of the schedule.
 //If the startCallback function is called, we put the scheduler into RUNNING state
+//Timer3A (fuel schedule 1) Compare Vector
 ISR(TIMER3_COMPA_vect) //fuelSchedule1
   {
     if (fuelSchedule1.Status == PENDING) //Check to see if this schedule is turn on