mate-driver/firmware/input.c

#include "input.h"

enum Edge {
    RISING = 0,
    FALLING = 1,
};

uint16_t volatile last_count;
enum Edge volatile next_edge;

volatile uint8_t signal_ok;

void input_init() {
    PORTD |= (1 << PD3);
    MCUCR |= (1 << ISC10) | (1 << ISC11);
    GIMSK |= (1 << INT1);

    TIMSK |= (1 << TOIE1);
    TCNT1 = 0;
    TCCR1B |= (1 << CS11); //Prescaler 8, enable Timer

    next_edge = RISING;
    last_count = 0;
    signal_ok = 0;
}


ISR(TIMER1_OVF_vect) {
    signal_ok = 0;
    PIND |= (1 << PD1);
}

ISR(INT1_vect) {
    signal_ok = 1;

    if(next_edge == RISING) {
        TCNT1 = 0;
        MCUCR &= ~(1 << ISC10); //Trigger on falling edge next
        next_edge = FALLING;
    } else if(next_edge == FALLING) {
        last_count = TCNT1;
        TCNT1 = 0;
        MCUCR |= (1 << ISC10); //Trigger on falling edge next
        next_edge = RISING;
    }
}

int16_t input_get_result() {
    int16_t tmp = last_count - 1500;
    if(tmp < -500) {
        tmp = -500;
    }
    if(tmp > 500) {
        tmp = 500;
    }
    return tmp;
}

uint8_t input_signal_ok() {
    return signal_ok;
}