#include "hardware.h" #include #include #include #include static Afsk *context; void hw_afsk_adcInit(int ch, Afsk *_context) { context = _context; ASSERT(ch <= 5); // Timer/Counter Control Register 1 (Timer1 settings, for short) // Set prescaler to clk/8 (2 MHz), CTC, top = ICR1 TCCR1A = 0; TCCR1B = BV(CS11) | BV(WGM13) | BV(WGM12); // Configure ICR1 to get 9.6KHz sampling rate ICR1 = ((CPU_FREQ / 8) / 9600) - 1; // Input capture register // Set reference to AVCC (5V), select pin ADMUX = BV(REFS0) | ch; DDRC &= ~BV(ch); PORTC &= ~BV(ch); DIDR0 |= BV(ch); // Set autotrigger on Timer1 Input capture flag ADCSRB = BV(ADTS2) | // Setting these three on (1-1-1) sets the ADC to BV(ADTS1) | // "Timer1 capture event" BV(ADTS0); // ADCSRA = BV(ADEN) | // ADC Enable BV(ADSC) | // ADC Start converting BV(ADATE) | // Enable autotriggering BV(ADIE) | // ADC Interrupt enable BV(ADPS2); // Enable prescaler flag 2 (1-0-0 = division by 16 = 1MHz) } // Declare ADC ISR bool hw_afsk_dac_isr; DECLARE_ISR(ADC_vect) { TIFR1 = BV(ICF1); afsk_adc_isr(context, ((int16_t)((ADC) >> 2) - 128)); if (hw_afsk_dac_isr) PORTD = afsk_dac_isr(context) & 0xF0; else PORTD = 128; }