![]() Serial.println(TIMSK0) // 1 = Timer overflow interrupt enabled for millis()/micros(). Serial.println(TCCR0B) // 3 = 64 prescaler. Serial.println(TCCR0A) // 3 = Fast PWM mode with a fixed timeout of 255. Find out what Timer0 has been initialised to. #define TIMER_0_COMPARE_B_POST_SCALER 100 Volatile uint32_t isr_t0b_delta_time = 0 Volatile uint32_t isr_t0a_delta_time = 0 Instead, you could use software post-scalers within the ISRs, something like this: volatile bool isr_t0a_flag = false You can't change the frequency though because that would change the update of millis() and micros(). That way they won't conflict with each other because there will be some time between each of the three interrupts (overflow, compare A and compare B). Simply set the compare interrupts to occur at 1/3rd and 2/3rds of the overflow period. It is possible to use the Timer0 compare interrupts without affecting the millis() and micros() functions. D4 is changed only once (244Hz)for every 2 changes of D5 (488Hz) Since you need 244Hz and 488Hz (exactly twice 244Hz), I think you can operate with only one of OCR0A or OCRB0 and do the work in one ISR only: #include In particular, since you use CTC mode, I think that TCNT0 will be cleared every time its value reaches OCR0A i.e. this may not be possible.Īctually, after reading the ATmega328P datasheet again, I am not sure that you can use both OCR0A and OCR0B in normal timer mode. I probably could put all the functionality I need in the same TIMER0_COMPA_vect, however I was trying to use that in a library I was writing and was trying to keep the functionality separate. They can be the same frequency, most likely. Update: After thinking about it, I'm realizing that it's not that I need two separate frequencies (though I just kinda wanted to know how, so this is good stuff) but I just need two separate interrupts, only using Timer0 (1 & 2 are already in use elsewhere). Set CS01 and CS00 bits for 64 prescaler set compare match register for 2khz increments TCNT0 = 0 //initialize counter value to 0 TCCR0A = 0 // set entire TCCR2A register to 0 But D5 (COMPB) is always what D4 (COMPA) is. I've setup some test code that should output a 244Hz signal on D4 and 488Hz on D5 (note, this is running at 8MHz). I realize it will make delay() and millis() not work but that's ok by me. I'm trying to understand how to fully use the COMPB vector ISR of Timer0 on the ATMega328 (standard Arduino core).
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