Add check for in progress scheduler. Clearer variable naming

scheduler.h

@@ -28,8 +28,8 @@ See page 136 of the processors datasheet: http://www.atmel.com/Images/doc2549.pd
 
 //#define clockspeed 16000000
 
-int schedule1Active; //Value=0 means do nothing, value=1 means call the startCallback, value=2 means call the endCallback
+int schedule1Status; //Value=0 means do nothing, value=1 means call the startCallback, value=2 means call the endCallback
-int schedule2Active;
+int schedule2Status; //As above, for 2nd scheduler
 unsigned long schedule1Duration; //How long (uS) after calling the start callback to we call the end callback
 unsigned long schedule2Duration;
 void (*schedule1StartCallback)(); //Start Callback function for schedule1

scheduler.ino

@@ -21,8 +21,8 @@ void initialiseScheduler()
     TCCR4A = 0x00;          //Timer2 Control Reg A: Wave Gen Mode normal
     TCCR4B = (1 << CS12);   //Timer2 Control Reg B: Timer Prescaler set to 256. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
    
-    schedule1Active = 0; 
+    schedule1Status = 0; 
-    schedule2Active = 0;
+    schedule2Status = 0;
   }
   
 /*
@@ -31,45 +31,47 @@ Args:
 startCallback: The function to be called once the timeout1 is reached
 timeout1: The number of uS in the future that the callback should be triggered
 duration: The number of uS before endCallback is called
-endCallback
+endCallback: This function is called once the duration time has been reached
 */
 void setSchedule1(void (*startCallback)(), unsigned long timeout, unsigned long duration, void(*endCallback)())
   {
     //We need to calculate the value to reset the timer to (preload) in order to achieve the desired overflow time
     //As the timer is ticking every 16uS (Time per Tick = (Prescale)*(1/Frequency)) 
     //TODO: Need to add check for timeout > 1048576 ????
+    if(schedule1Status == 2) { return; } //Check that we're note already part way through a schedule
     TCNT3 = 65536 - (timeout / 16); //Each tick occurs every 16uS with a 256 prescaler so divide the timeout by 16 to get ther required number of ticks. Subtract this from the total number of tick (65536 for 16-bit timer)
     schedule1Duration = duration;
     schedule1StartCallback = startCallback; //Name the start callback function
     schedule1EndCallback = endCallback; //Name the start callback function
-    schedule1Active = 1; //Turn this schedule on and set it
+    schedule1Status = 1; //Turn this schedule on and set it
   }
   
 //As above, but for schedule2
 void setSchedule2(void (*startCallback)(), unsigned long timeout, unsigned long duration, void(*endCallback)())
   {
     //TODO: Need to add check for timeout > 1048576 ????
+    if(schedule2Status == 2) { return; } //Check that we're note already part way through a schedule
     TCNT4 = 65536 - (timeout / 16); //Each tick occurs every 16uS with a 256 prescaler so divide the timeout by 16 to get ther required number of ticks. Subtract this from the total number of tick (65536 for 16-bit timer)
     schedule2Duration = duration;
     schedule2StartCallback = startCallback; //Name the callback function
     schedule2EndCallback = endCallback; //Name the callback function
-    schedule2Active = 1; //Turn this schedule on
+    schedule2Status = 1; //Turn this schedule on
   }
   
 //Timer3 (schedule 1) Overflow Interrupt Vector
 //This needs to call the callback function if one has been provided and rest the timer
 ISR(TIMER3_OVF_vect)
   {
-    if (schedule1Active == 1) //Check to see if this schedule is turn on
+    if (schedule1Status == 1) //Check to see if this schedule is turn on
     {
       schedule1StartCallback(); //Replace with user provided callback
-      schedule1Active = 2; //Turn off the callback 
+      schedule1Status = 2; //Turn off the callback 
       TCNT3 = 65536 - (schedule1Duration / 16);
     }
-    else if (schedule1Active == 2)
+    else if (schedule1Status == 2)
     {
        schedule1EndCallback();
-       schedule1Active = 0; //Turn off the callback
+       schedule1Status = 0; //Turn off the callback
        TCNT3 = 0;           //Reset Timer to 0 out of 255
     }
     
@@ -79,16 +81,16 @@ ISR(TIMER3_OVF_vect)
 //AS above for schedule2
 ISR(TIMER4_OVF_vect)
   {
-    if (schedule2Active == 1) //A value of 1 means call the start callback
+    if (schedule2Status == 1) //A value of 1 means call the start callback
     {
       schedule2StartCallback();
-      schedule2Active = 2; //Set to call the end callback on the next run
+      schedule2Status = 2; //Set to call the end callback on the next run
       TCNT4 = 65536 - (schedule2Duration / 16); 
     }
-    else if (schedule2Active == 2)
+    else if (schedule2Status == 2)
     {
        schedule2EndCallback();
-       schedule2Active = 0; //Turn off the callback
+       schedule2Status = 0; //Turn off the callback
        TCNT4 = 0;           //Reset Timer to 0 out of 255
     }