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atmega-geiger/src/radiation.c

52 lines
1.1 KiB

/**
* 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);
}