esp32-alarm-clock/main/wifi.c

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

#include <stdint.h>
#include <esp_wifi.h>
#include <esp_err.h>
#include <esp_log.h>
#include <string.h>

#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <freertos/event_groups.h>
#include <lwip/ip_addr.h>

#include "configuration.h"

#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT      BIT1
#define TAG "wifi"
#define MAX_CONNECT_RETRIES 15

static EventGroupHandle_t wifi_event_group;
static int retries = 0;

static void wifi_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data) {
    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
        esp_wifi_connect();
    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
        if (retries < MAX_CONNECT_RETRIES) {
            esp_wifi_connect();
            retries++;
            ESP_LOGI(TAG, "retry to connect to the AP");
        } else {
            xEventGroupSetBits(wifi_event_group, WIFI_FAIL_BIT);
        }
        ESP_LOGI(TAG,"connect to the AP fail");
    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
        ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
        retries = 0;
        xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
    }
}


void wifi_init() {
    wifi_event_group = xEventGroupCreate();
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
    esp_netif_t* netif = esp_netif_create_default_wifi_sta();
    esp_netif_dhcpc_stop(netif);

    esp_netif_ip_info_t ip_info;
    ipaddr_aton(IP_ADDRESS, (struct ip_addr *) &ip_info.ip);
    ipaddr_aton(GATEWAY, (struct ip_addr *) &ip_info.gw);
    ipaddr_aton(NETMASK, (struct ip_addr *) &ip_info.netmask);

    esp_netif_set_ip_info(netif, &ip_info);

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));

    esp_event_handler_instance_t instance_any_id;
    esp_event_handler_instance_t instance_got_ip;
    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &wifi_event_handler, NULL, &instance_any_id));
    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler, NULL, &instance_got_ip));

    wifi_config_t wifi_config = {
            .sta = {
                    .ssid = WIFI_ESSID,
                    .password = WIFI_PASSWORD
            },
    };

    wifi_config.sta.threshold.authmode = WIFI_AUTH_WPA2_PSK;
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
}

uint8_t wifi_start() {
    ESP_ERROR_CHECK(esp_wifi_start());

    xEventGroupWaitBits(wifi_event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
                        pdFALSE, pdFALSE, portMAX_DELAY);
    EventBits_t event_bits = xEventGroupGetBits(wifi_event_group);
    ESP_ERROR_CHECK(esp_event_handler_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler));
    ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, &wifi_event_handler));
    vEventGroupDelete(wifi_event_group);
    return event_bits & WIFI_CONNECTED_BIT;
}

void wifi_stop() {
    esp_wifi_disconnect();
    esp_wifi_stop();
}