mirror of https://github.com/rusefi/speeduino.git
65 lines
2.9 KiB
C++
65 lines
2.9 KiB
C++
/*
|
|
Timers are used for having actions performed repeatedly at a fixed interval (Eg every 100ms)
|
|
They should not be confused with Schedulers, which are for performing an action once at a given point of time in the future
|
|
|
|
Timers are typically low resolution (Compared to Schedulers), with maximum frequency currently being approximately every 10ms
|
|
*/
|
|
|
|
void initialiseTimers()
|
|
{
|
|
//Configure Timer2 for our low-freq interrupt code.
|
|
TCCR2B = 0x00; //Disbale Timer2 while we set it up
|
|
TCNT2 = 99; //Preload timer2 with 100 cycles, leaving 156 till overflow.
|
|
TIFR2 = 0x00; //Timer2 INT Flag Reg: Clear Timer Overflow Flag
|
|
TIMSK2 = 0x01; //Timer2 Set Overflow Interrupt enabled.
|
|
TCCR2A = 0x00; //Timer2 Control Reg A: Wave Gen Mode normal
|
|
TCCR2B = ((1 << CS10) | (1 << CS11) | (1 << CS12)); //Timer2 Set Prescaler to 5 (101), 1024 mode.
|
|
}
|
|
|
|
|
|
//Timer2 Overflow Interrupt Vector, called when the timer overflows.
|
|
//Executes every ~10ms.
|
|
ISR(TIMER2_OVF_vect)
|
|
{
|
|
|
|
//Increment Loop Counters
|
|
loop250ms++;
|
|
loopSec++;
|
|
|
|
|
|
//Loop executed every 250ms loop (10ms x 25 = 250ms)
|
|
//Anything inside this if statement will run every 250ms.
|
|
if (loop250ms == 25)
|
|
{
|
|
loop250ms = 0; //Reset Counter.
|
|
}
|
|
|
|
//Loop executed every 1 second (10ms x 100 = 1000ms)
|
|
if (loopSec == 100)
|
|
{
|
|
loopSec = 0; //Reset counter.
|
|
|
|
//**************************************************************************************************************************************************
|
|
//This updates the runSecs variable
|
|
//If the engine is running or cranking, we need ot update the run time counter.
|
|
if ((BIT_CHECK(currentStatus.engine, BIT_ENGINE_RUN) || BIT_CHECK(currentStatus.engine, BIT_ENGINE_CRANK)))
|
|
{ //NOTE - There is a potential for a ~1sec gap between engine crank starting and ths runSec number being incremented. This may delay ASE!
|
|
if (currentStatus.runSecs <= 254) //Ensure we cap out at 255 and don't overflow. (which would reset ASE)
|
|
{ currentStatus.runSecs++; } //Increment our run counter by 1 second.
|
|
}
|
|
//**************************************************************************************************************************************************
|
|
//This records the number of main loops the system has completed in the last second
|
|
currentStatus.loopsPerSecond = mainLoopCount;
|
|
mainLoopCount = 0;
|
|
//**************************************************************************************************************************************************
|
|
//increament secl (secl is simply a counter that increments every second and is used to track whether the system has unexpectedly reset
|
|
currentStatus.secl++;
|
|
|
|
|
|
}
|
|
//Reset Timer2 to trigger in another ~10ms
|
|
TCNT2 = 99; //Preload timer2 with 100 cycles, leaving 156 till overflow.
|
|
TIFR2 = 0x00; //Timer2 INT Flag Reg: Clear Timer Overflow Flag
|
|
|
|
}
|