atmega-geiger/src/main.c

#include "sevenseg.h"
#include <avr/interrupt.h>
#include <util/atomic.h>
#include <util/delay.h>
#include <avr/sleep.h>
#include "time_base.h"
#include "high_voltage.h"
#include "radiation.h"
#include "user_interface.h"
#include "ssd1306.h"

/* globals */
volatile bool req_update_display = false;
volatile bool status_weak_battery = false;
volatile uint8_t disp_show_tick_mark = 0;

static void shutdown_due_to_weak_battery();


void __attribute__((noreturn)) main()
{
    init_user_interface();

    show_loading_screen(0, true);

    init_timebase();
    init_radiation();

    // --- let's go ---
    sei();

    // this needs interrupts enabled
    init_high_voltage();

    for (;;) {
        // one tick makes the marker lit for 10 ms (more in practice, plus display ghosting latency)
        for (uint8_t i = 0; i < 10; i++) {
            _delay_ms(10);
            if (disp_show_tick_mark == 1) {
                ssd1306_setColor(0xFFFF);
                ssd1306_fillRect(124, 0, 127, 3);
                disp_show_tick_mark = 2;
            } else if (disp_show_tick_mark == 2) {
                disp_show_tick_mark = 0;
                ssd1306_setColor(0x0000);
                ssd1306_fillRect(124, 0, 127, 3);
                ssd1306_setColor(0xFFFF);
            }
        }

        // check if redraw is needed
//        bool update_display = true;
//        ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
//            update_display = req_update_display;
//            req_update_display = false;
//        }

//        if (update_display) {
        show_current_radiation();
//        }

        if (status_weak_battery) {
            shutdown_due_to_weak_battery();
        }
    }
}


void __attribute__((noreturn)) shutdown_due_to_weak_battery()
{
    cli();
    hv_disable();

    show_empty_battery();
    // try to preserve power; but the display will still drain the battery.
    // we should probably shut it off too.

    _delay_ms(2000);
    turn_off_display();

    for (;;) {
        sleep_enable();
        sleep_cpu();
    }
}