esp32-alarm-clock/main/time_display.c

/*
 * SPDX-FileCopyrightText: 2022 Helmut Pozimski <helmut@pozimski.eu>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 */
 
#include <stdint.h>

#include <esp_err.h>
#include <freertos/FreeRTOS.h>
#include <freertos/event_groups.h>

#include "tm1637.h"
#include "ds3231.h"
#include "configuration.h"

static void update_display(uint8_t hour, uint8_t minute) {
    if (hour < 10) {
        tm1637_set_segment(10, 0, 1);
        tm1637_set_segment(hour, 1, 1);
    } else {
        tm1637_set_segment(hour / 10, 0, 1);
        tm1637_set_segment(hour % 10, 1, 1);
    }

    if (minute < 10) {
        tm1637_set_segment(0, 2, 1);
        tm1637_set_segment(minute, 3, 1);
    } else {
        tm1637_set_segment(minute / 10, 2, 1);
        tm1637_set_segment(minute % 10, 3, 1);
    }
}

static struct tm *convert_to_local(struct tm *timeinfo) {
    setenv("TZ", "GMT+0GMT+0", 1);
    tzset();
    time_t epoch_time = mktime(timeinfo);
    setenv("TZ", LOCAL_TIMEZONE, 1);
    tzset();
    return localtime(&epoch_time);
}

static uint8_t max(uint8_t a, uint8_t b) {
    return (a > b) ? a : b;
}

static uint16_t determine_sleep_time(struct tm *local_time) {
    uint8_t wakeup_time_sec;
    wakeup_time_sec = 60 - local_time->tm_sec;
    wakeup_time_sec = max(wakeup_time_sec, 1);
    return wakeup_time_sec * 1000;
}

void display_update_task(void *pvParameters) {
	struct tm current_time;
	while(1) {
		ds3231_read_date_time(&current_time);
		struct tm *local_time = convert_to_local(&current_time);
		setenv("TZ", "GMT+0GMT+0", 1);
		tzset();
		update_display(local_time->tm_hour, local_time->tm_min);
		vTaskDelay(determine_sleep_time(local_time) / portTICK_PERIOD_MS);
	}
	vTaskDelete( NULL );
}