mirror of https://github.com/rusefi/speeduino.git
85 lines
4.4 KiB
C++
85 lines
4.4 KiB
C++
/*
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Speeduino - Simple engine management for the Arduino Mega 2560 platform
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Copyright (C) Josh Stewart
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A full copy of the license may be found in the projects root directory
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*/
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/*
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Timers are used for having actions performed repeatedly at a fixed interval (Eg every 100ms)
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They should not be confused with Schedulers, which are for performing an action once at a given point of time in the future
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Timers are typically low resolution (Compared to Schedulers), with maximum frequency currently being approximately every 10ms
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*/
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#include "timers.h"
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#include "globals.h"
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void initialiseTimers()
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{
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//Configure Timer2 for our low-freq interrupt code.
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TCCR2B = 0x00; //Disbale Timer2 while we set it up
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TCNT2 = 131; //Preload timer2 with 131 cycles, leaving 125 till overflow. As the timer runs at 125Khz, this causes overflow to occur at 1Khz = 1ms
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TIFR2 = 0x00; //Timer2 INT Flag Reg: Clear Timer Overflow Flag
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TIMSK2 = 0x01; //Timer2 Set Overflow Interrupt enabled.
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TCCR2A = 0x00; //Timer2 Control Reg A: Wave Gen Mode normal
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/* Now configure the prescaler to CPU clock divided by 128 = 125Khz */
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TCCR2B |= (1<<CS22) | (1<<CS20); // Set bits
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TCCR2B &= ~(1<<CS21); // Clear bit
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}
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//Timer2 Overflow Interrupt Vector, called when the timer overflows.
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//Executes every ~1ms.
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ISR(TIMER2_OVF_vect)
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{
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//Increment Loop Counters
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loop250ms++;
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loopSec++;
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//Overdwell check
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targetOverdwellTime = currentLoopTime - (1000 * configPage2.dwellLimit); //Set a target time in the past that all coil charging must have begun after. If the coil charge began before this time, it's been running too long
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targetTachoPulseTime = currentLoopTime - (1500);
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//Check first whether each spark output is currently on. Only check it's dwell time if it is
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if(ignitionSchedule1.Status == RUNNING) { if(ignitionSchedule1.startTime < targetOverdwellTime) { endCoil1Charge(); } if(ignitionSchedule1.startTime < targetTachoPulseTime) { digitalWrite(pinTachOut, HIGH); } }
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if(ignitionSchedule2.Status == RUNNING) { if(ignitionSchedule2.startTime < targetOverdwellTime) { endCoil2Charge(); } if(ignitionSchedule2.startTime < targetTachoPulseTime) { digitalWrite(pinTachOut, HIGH); } }
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if(ignitionSchedule3.Status == RUNNING) { if(ignitionSchedule3.startTime < targetOverdwellTime) { endCoil3Charge(); } if(ignitionSchedule3.startTime < targetTachoPulseTime) { digitalWrite(pinTachOut, HIGH); } }
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if(ignitionSchedule4.Status == RUNNING) { if(ignitionSchedule4.startTime < targetOverdwellTime) { endCoil4Charge(); } if(ignitionSchedule4.startTime < targetTachoPulseTime) { digitalWrite(pinTachOut, HIGH); } }
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//Loop executed every 250ms loop (1ms x 250 = 250ms)
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//Anything inside this if statement will run every 250ms.
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if (loop250ms == 250)
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{
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loop250ms = 0; //Reset Counter.
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}
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//Loop executed every 1 second (1ms x 1000 = 1000ms)
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if (loopSec == 1000)
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{
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loopSec = 0; //Reset counter.
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//**************************************************************************************************************************************************
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//This updates the runSecs variable
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//If the engine is running or cranking, we need ot update the run time counter.
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if (BIT_CHECK(currentStatus.engine, BIT_ENGINE_RUN))
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{ //NOTE - There is a potential for a ~1sec gap between engine crank starting and ths runSec number being incremented. This may delay ASE!
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if (currentStatus.runSecs <= 254) //Ensure we cap out at 255 and don't overflow. (which would reset ASE)
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{ currentStatus.runSecs++; } //Increment our run counter by 1 second.
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}
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//**************************************************************************************************************************************************
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//This records the number of main loops the system has completed in the last second
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currentStatus.loopsPerSecond = mainLoopCount;
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mainLoopCount = 0;
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//**************************************************************************************************************************************************
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//increament secl (secl is simply a counter that increments every second and is used to track whether the system has unexpectedly reset
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currentStatus.secl++;
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}
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//Reset Timer2 to trigger in another ~1ms
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TCNT2 = 131; //Preload timer2 with 100 cycles, leaving 156 till overflow.
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TIFR2 = 0x00; //Timer2 INT Flag Reg: Clear Timer Overflow Flag
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}
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