I am looking at this for a few hours now and I simply can't see why this setup does not result in free running ADC. I'm on attiny85.
void setup_adc()
{
// Init ADCSRA and B
ADCSRA = 0;
ADCSRB = 0;
// Set ADC to do 8 bit resolution (left align and we will only use ADCH)
sbi(ADMUX, ADLAR);
// Set PB2 (ADC1) as input
sbi(ADMUX, MUX0);
// Disable digital input on PB2, we will only need it for ADC
sbi(DIDR0, ADC1D);
// Perform clk/128 conversions per second (which is more than enough)
sbi3(ADCSRA, ADPS0, ADPS1, ADPS2);
// Choose pin change interrupt as ADC trigger
//sbi2(ADCSRB, ADTS1, ADTS2); Free running for now
// Finally enable auto-trigger, conversion complete interrupt and ADC as a whole
sbi3(ADCSRA, ADATE, ADIE, ADEN);
}I'm not getting any calls to the ADC complete interrupt handler:
ISR(ADC_vect)
{
adcData = ADCH;
adcDataAvailable = 1;
}
I am already using PWM on timer 0 and 1 (for some reason PWM on timer 1 does not seem to run without start PWM on timer 0).
Anyway, my question is whether anyone can see what I am missing in my setup ? I'm clueless. Tried different examples. Setting ADCSRA and B to 0 is the result of being desperate, that shouldn't be necessary, right ?
Many thanks,
Henk
PS: I do start a first conversion:
setup_pwm(); setup_adc(); // Turn on Pin Change interrupt //sbi(GIMSK, PCIE); // Enable external interrupt on PB2 //sbi(PCMSK, PCINT2); //clearNote(); // Start conversion sbi(ADCSRA, ADSC); sei();
