/**
 * Radiation counting
 */

#include "radiation.h"
#include "time_base.h"
#include "global_state.h"
#include "iopins.h"

#include <avr/interrupt.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#define MEAS_BIN_COUNT 120
typedef uint8_t meas_bin_t;
#define MEAS_MAX_COUNT 255

/// measurements in the last X seconds
static volatile meas_bin_t measurements[MEAS_BIN_COUNT];
/// Currently active measurement bin, increments once per second
static volatile uint8_t meas_bin = 0;

// geiger tube pin change interrupt
ISR(INT0_vect)
{
    if (measurements[meas_bin] < MEAS_MAX_COUNT) {
        measurements[meas_bin]++;
    }
    req_update_display = true;
}

void second_callback_irq()
{
    meas_bin++;
    if (meas_bin >= MEAS_BIN_COUNT) {
        meas_bin = 0;
    }
    measurements[meas_bin] = 0;
    req_update_display = true;
}

void init_radiation() {
    // clear the measurement buffer
    memset((void*) measurements, 0, sizeof(measurements));

    as_input(D2);

    // using INT0 - arduino pin D2
    EICRA = _BV(ISC01) | _BV(ISC00); // rising edge
    EIMSK = _BV(INT0);
}