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Change the way some of the avr2560 timers are initialised

This commit is contained in:
Josh Stewart 2019-04-01 16:10:10 +11:00
parent 465dda0c7a
commit f02fd2c26a
1 changed files with 9 additions and 10 deletions
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19
speeduino/board_avr2560.ino
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@ -16,12 +16,12 @@ void initBoard()
***********************************************************************************************************
* Auxilliaries
*/
//PWM used by the Boost and VVT outputs
//PWM used by the Boost and VVT outputs. C Channel is used by ign5
TCCR1B = 0x00; //Disbale Timer1 while we set it up
TCNT1 = 0; //Reset Timer Count
TIFR1 = 0x00; //Timer1 INT Flag Reg: Clear Timer Overflow Flag
TCCR1A = 0x00; //Timer1 Control Reg A: Wave Gen Mode normal (Simply counts up from 0 to 65535 (16-bit int)
TCCR1B = (1 << CS12); //Timer1 Control Reg B: Timer Prescaler set to 256. 1 tick = 16uS. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
TIFR1 = (1 << OCF1A) | (1<<OCF1B) | (1<<OCF1C) | (1<<TOV1) | (1<<ICF1); //Clear the compare flags, overflow flag and external input flag bits
boost_pwm_max_count = 1000000L / (16 * configPage6.boostFreq * 2); //Converts the frequency in Hz to the number of ticks (at 16uS) it takes to complete 1 cycle. The x2 is there because the frequency is stored at half value (in a byte) to allow freqneucies up to 511Hz
vvt_pwm_max_count = 1000000L / (16 * configPage6.vvtFreq * 2); //Converts the frequency in Hz to the number of ticks (at 16uS) it takes to complete 1 cycle
@ -33,12 +33,12 @@ void initBoard()
//Configure Timer2 for our low-freq interrupt code.
TCCR2B = 0x00; //Disbale Timer2 while we set it up
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
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
/* Now configure the prescaler to CPU clock divided by 128 = 125Khz */
TCCR2B |= (1<<CS22) | (1<<CS20); // Set bits
TCCR2B &= ~(1<<CS21); // Clear bit
TCCR2B &= ~(1<<CS21); // Clear bit. Shouldn't be needed as initial value is 0 anyway, but best to play it safe
TIFR2 = (1 << OCF2A) | (1<<OCF2B) | (1<<TOV2); //Clear the compare flag bits and overflow flag bit
//Enable the watchdog timer for 2 second resets (Good reference: https://tushev.org/articles/arduino/5/arduino-and-watchdog-timer)
//Boooooooooo WDT is currently broken on Mega 2560 bootloaders :(
@ -52,18 +52,17 @@ void initBoard()
//Fuel Schedules, which uses timer 3
TCCR3B = 0x00; //Disable Timer3 while we set it up
TCNT3 = 0; //Reset Timer Count
TIFR3 = 0x00; //Timer3 INT Flag Reg: Clear Timer Overflow Flag
TCCR3A = 0x00; //Timer3 Control Reg A: Wave Gen Mode normal
TCCR3B = (1 << CS12); //Timer3 Control Reg B: Timer Prescaler set to 256. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
//TCCR3B = 0x03; //Timer3 Control Reg B: Timer Prescaler set to 64. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
TCCR3B = (1 << CS12); //Same as: 0x03. Timer3 Control Reg B: Timer Prescaler set to 256. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
TIFR3 = (1 << OCF3A) | (1<<OCF3B) | (1<<OCF3C) | (1<<TOV3) | (1<<ICF3); //Clear the compare flags, overflow flag and external input flag bits
//Ignition Schedules, which uses timer 5. This is also used by the fast version of micros(). If the speed of this timer is changed from 4uS ticks, that MUST be changed as well. See globals.h and timers.ino
TCCR5B = 0x00; //Disable Timer5 while we set it up
TCNT5 = 0; //Reset Timer Count
TCCR5A = 0x00; //Timer5 Control Reg A: Wave Gen Mode normal
TCCR5B = (1 << CS11) | (1 << CS10); //Timer5 Control Reg B: Timer Prescaler set to 64. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
TIFR5 |= (1 << OCF5A) | (1<<OCF5B) | (1<<OCF5C); //Clear the compare flag bits
TIFR5 = (1 << OCF5A) | (1<<OCF5B) | (1<<OCF5C) | (1<<TOV5) | (1<<ICF5); //Clear the compare flags, overflow flag and external input flag bits
#if defined(TIMER5_MICROS)
TIMSK5 |= (1 << TOIE5); //Enable the timer5 overflow interrupt (See timers.ino for ISR)
TIMSK0 &= ~_BV(TOIE0); // disable timer0 overflow interrupt
@ -72,9 +71,9 @@ void initBoard()
//The remaining Schedules (Schedules 4 for fuel and ignition) use Timer4
TCCR4B = 0x00; //Disable Timer4 while we set it up
TCNT4 = 0; //Reset Timer Count
TIFR4 = 0x00; //Timer4 INT Flag Reg: Clear Timer Overflow Flag
TCCR4A = 0x00; //Timer4 Control Reg A: Wave Gen Mode normal
TCCR4B = (1 << CS12); //Timer4 Control Reg B: aka Divisor = 256 = 122.5HzTimer Prescaler set to 256. Refer to http://www.instructables.com/files/orig/F3T/TIKL/H3WSA4V7/F3TTIKLH3WSA4V7.jpg
TIFR4 = (1 << OCF4A) | (1<<OCF4B) | (1<<OCF4C) | (1<<TOV4) | (1<<ICF4); //Clear the compare flags, overflow flag and external input flag bits
}