I'm trying to run two functions 'similtaniously' via interrupts:
1) Measure ADC via timing of timer 0 (100Hz) and show results on pin 0-5
2) Blink a led via timer 1 (10Hz) on pin 6.
Problem seems to be that the ISR of timer 1 blocks the function, so nothing else is executed. Here is the code:
(Please don't be offended by any styling mistakes, the code is under development)
#define F_CPU 16000000UL // 16MHz Clock speed
#include <avr/io.h>
#include <avr/interrupt.h>
void ADC_init(void);
void SetTimer0(void);
void SetTimer1(void);
int main(void)
{
DDRB |= (1<<DDB0) + (1<<DDB1) + (1<<DDB2) + (1<<DDB3) + (1<<DDB4) + (1<<DDB5) + (1<<DDB6);
PORTB = 0b00000000;
DDRB &= ~(1<<DDB7);
ADC_init();
SetTimer0();
SetTimer1();
while(1){
}
}
void ADC_init(void)
{
cli();
// Select Vref=AVcc
// and set left adjust result
// select pin ADC0 (PC0)
ADMUX |= (1<<REFS0)|(1<<ADLAR);
//and enable ADC
//enable ADC interupt
//enable autotriggering
//set prescaller to 128
ADCSRA |= (1<<ADEN) | (1<<ADATE) | (1<<ADIE) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
//set ADC trigger source - Timer0 compare match A
ADCSRB |= (1<<ADTS1)|(1<<ADTS0);
// StartADC
ADCSRA |= (1<<ADSC);
sei();
}
//initialize timer0 match A on 100hz
void SetTimer0(void)
{
cli();
TCCR0A = 0; // set entire TCCR0A register to 0
TCCR0B = 0; // same for TCCR0B
TCNT0 = 0; // initialize counter value to 0
// set compare match register for 100Hz increments
OCR0A = 155; // = 16000000 / (1024 * 100.16025641025641)-1
// toggle PD6/OC0A pin on compare match
TCCR0A |=(1<<COM0A0)|(1<<WGM01);
//Set CTC mode
TCCR0B |= (1 << WGM01);
// Set CS02, CS01 and CS00 bits for 1024 prescaler
TCCR0B |= (1 << CS02) | (0 << CS01) | (1 << CS00);
// enable timer compare interrupt
TIMSK0 |= (1 << OCIE0A);
sei();
}
//initialize timer1 10hz
void SetTimer1(void){
cli();
TCCR1A = 0; // set entire TCCR1A register to 0
TCCR1B = 0; // same for TCCR1B
TCNT1 = 0; // initialize counter value to 0
// set compare match register for 10 Hz increments
OCR1A = 24999; // = 16000000 / (64 * 10) - 1 (must be <65536)
// turn on CTC mode
TCCR1B |= (1 << WGM12);
// Set CS12, CS11 and CS10 bits for 64 prescaler
TCCR1B |= (0 << CS12) | (1 << CS11) | (1 << CS10);
// enable timer compare interrupt
TIMSK1 |= (1 << OCIE1A);
sei();
}
// ADC done interrupt
ISR(ADC_vect)
{
// Clear timer compare match flag
TIFR0=(1<<OCF0A);
// save ADC measurement
uint16_t val = ADC;
// show ADC results
if (val < 100)
{ PORTB = 0b00000000; }
else if (val < 300)
{ PORTB = 0b00000001; }
else if (val < 550)
{ PORTB = 0b00000011; }
else if (val < 850)
{ PORTB = 0b00000111; }
else if (val < 1020)
{ PORTB = 0b00001111; }
else
{ PORTB = 0b00011111; }
}
ISR(TIMER1_COMPA_vect)
{
//PORTB ^= PINB5;
static uint16_t on = 0;
if (on == 1){
PORTB = 0b00100000;
on = 0;
}
else {
PORTB = 0b00000000;
on = 1;
}
}
When the SetTimer1()
function is disabled the DCA runs as expected. So individually are are both ISR's working fine, but together not. Could someone help me solve this problem?
You have output compare interrupt enabled fro Timer0:
// enable timer compare interrupt
TIMSK0 |= (1 << OCIE0A);
but no ISR handler for that interrupt.
The default __bad_interrupt handler just performs jump to zero interrupt vector, i.e. restarts the program.
That means if you have an interrupt enabled there should be an ISR for that interrupt.