用C语言写出esp32关于ota的程序

以下是一个简单的 ESP32 OTA 程序，使用 C 语言编写。它通过 Wi-Fi 连接到网络，下载固件并更新设备。

#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_ota_ops.h"
#include "esp_http_client.h"

#define FIRMWARE_URL "http://example.com/firmware.bin"

static const char *TAG = "OTA";

void ota_task(void *pvParameter)
{
    ESP_LOGI(TAG, "Starting OTA task...");

    const esp_partition_t *update_partition = esp_ota_get_next_update_partition(NULL);
    if (update_partition == NULL) {
        ESP_LOGE(TAG, "Failed to get next update partition...");
        vTaskDelete(NULL);
        return;
    }

    ESP_LOGI(TAG, "Writing to partition subtype %d at offset 0x%x",
             update_partition->subtype, update_partition->address);

    esp_http_client_config_t config = {
        .url = FIRMWARE_URL,
        .cert_pem = NULL,
    };
    esp_http_client_handle_t client = esp_http_client_init(&config);
    esp_err_t err = esp_http_client_open(client, 0);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "Failed to open HTTP connection: %s", esp_err_to_name(err));
        esp_http_client_cleanup(client);
        vTaskDelete(NULL);
        return;
    }

    esp_ota_handle_t ota_handle = 0;
    err = esp_ota_begin(update_partition, OTA_SIZE_UNKNOWN, &ota_handle);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "Failed to begin OTA: %s", esp_err_to_name(err));
        esp_http_client_cleanup(client);
        vTaskDelete(NULL);
        return;
    }

    char buffer[1024];
    int total_read = 0;
    int content_length = esp_http_client_fetch_headers(client);
    while (1) {
        int read_len = esp_http_client_read(client, buffer, sizeof(buffer));
        if (read_len <= 0) {
            break;
        }
        total_read += read_len;
        esp_err_t write_err = esp_ota_write(ota_handle, buffer, read_len);
        if (write_err != ESP_OK) {
            ESP_LOGE(TAG, "Failed to write OTA data: %s", esp_err_to_name(write_err));
            esp_http_client_cleanup(client);
            esp_ota_end(ota_handle);
            vTaskDelete(NULL);
            return;
        }
    }

    ESP_LOGI(TAG, "Total binary data length written: %d", total_read);

    if (esp_http_client_is_complete_data_received(client) != true ||
        total_read != content_length) {
        ESP_LOGE(TAG, "OTA download failed: incomplete data received");
        esp_http_client_cleanup(client);
        esp_ota_end(ota_handle);
        vTaskDelete(NULL);
        return;
    }

    err = esp_ota_end(ota_handle);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "Failed to end OTA: %s", esp_err_to_name(err));
        esp_http_client_cleanup(client);
        vTaskDelete(NULL);
        return;
    }

    err = esp_ota_set_boot_partition(update_partition);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "Failed to set boot partition: %s", esp_err_to_name(err));
        esp_http_client_cleanup(client);
        vTaskDelete(NULL);
        return;
    }

    ESP_LOGI(TAG, "OTA complete, restarting...");
    esp_http_client_cleanup(client);
    esp_restart();
}

void app_main()
{
    ESP_LOGI(TAG, "ESP32 OTA example");

    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
    ESP_ERROR_CHECK(esp_wifi_start());

    wifi_config_t wifi_config = {
        .sta = {
            .ssid = "YOUR_WIFI_SSID",
            .password = "YOUR_WIFI_PASSWORD",
        },
    };
    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
    ESP_ERROR_CHECK(esp_wifi_connect());

    xTaskCreate(&ota_task, "ota_task", 8192, NULL, 5, NULL);
}

该程序连接到 Wi-Fi 网络，然后下载固件并更新设备。要使用此程序，请将 `FIRMWARE_URL` 替换为固件文件的 URL，并将 `YOUR_WIFI_SSID` 和 `YOUR_WIFI_PASSWORD` 替换为您的 Wi-Fi SSID 和密码。

请注意，此程序仅用于示例目的。在实际使用中，您需要对其进行修改和适当的错误处理。