ESP32 Forum

Code: Select all

const esp_http_client_config_t s_defaultTomtomConfig = {
    .url = url,
    .auth_type = API_AUTH_TYPE,
    .method = API_METHOD,
    .event_handler = tomtomHandler,
    .crt_bundle_attach = esp_crt_bundle_attach,
    .user_data = &reqResult,
};

Code: Select all

void app_main(void)
{
    // Initialize NVS
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
      ESP_ERROR_CHECK(nvs_flash_erase());
      ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK(ret);
    // initialize tcp/ip stack
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
    esp_netif_create_default_wifi_sta();
    // establish wifi connection
    wifi_init_config_t default_wifi_cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&default_wifi_cfg));
    ESP_ERROR_CHECK(establishWifiConnection());

    esp_tls_t *tls = esp_tls_init();
    if (!tls) {
        printf("failed to allocate esp_tls handle!");
        fflush(stdout);
        for (int countdown = 10; countdown >= 0; countdown--) {
            vTaskDelay(1000 / portTICK_PERIOD_MS);
        }
    }

    uint result = 0;
    char *var = "https://api.tomtom.com/traffic/services/4/flowSegmentData/relative0/10/json?key=(apikey)&point=34.456,-119.976&unit=mph&openLr=true";
    ESP_ERROR_CHECK(tomtomRequestPerform(&result, var));
    printf("speed: %d\n", result);
    fflush(stdout);

    for (;;) {
      vTaskDelay(INT_MAX);
    }
}

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/**
 * Requires:
 * - WIFI connection (establishWifiConnection called).
 * - TLS initialized (esp_tls_init called).
 */
esp_err_t tomtomRequestPerform(uint *result, const char *url) {
    if (result == NULL) {
        return ESP_FAIL;
    }

    struct requestResult reqResult = {
        .error = ESP_FAIL,
        .result = 0,
    };

    const esp_http_client_config_t s_defaultTomtomConfig = {
        .url = url,
        .auth_type = API_AUTH_TYPE,
        .method = API_METHOD,
        .event_handler = tomtomHandler,
        .crt_bundle_attach = esp_crt_bundle_attach,
        .user_data = &reqResult,
    };

    printf("%s\n", s_defaultTomtomConfig.url);
    esp_http_client_handle_t httpClientHandle = esp_http_client_init(&s_defaultTomtomConfig);
    if (esp_http_client_perform(httpClientHandle) == ESP_FAIL) { // blocks when requesting
        return ESP_FAIL;
    }
    esp_http_client_cleanup(httpClientHandle);
    *result = reqResult.result;
    return ESP_OK;
}

Code: Select all

/**
 * Handler for recieving responses from the TomTom API.
 */
esp_err_t tomtomHandler(esp_http_client_event_t *evt) {
    struct requestResult *reqResult = (struct requestResult *) evt->user_data;
    static char buffer[RCV_BUFFER_SIZE];
    static uint content_size;
    switch (evt->event_id) {
        case HTTP_EVENT_ON_CONNECTED:
            memset(buffer, 0, RCV_BUFFER_SIZE);
            content_size = 0;
            break;
        case HTTP_EVENT_ON_DATA:
            if (evt->data == NULL) {
            } else {
                memcpy(buffer + content_size, evt->data, evt->data_len);
                content_size += evt->data_len;
            }
            break;
        case HTTP_EVENT_ON_FINISH:
            cJSON *json = cJSON_Parse(buffer);
            json = json->child;
            for (cJSON *curr = json->child; !cJSON_IsNull(curr); curr = curr->next) {
                if (strcmp(curr->string, "currentSpeed") != 0) {
                    continue;
                }
                if (!cJSON_IsNumber(curr)) {
                    reqResult->error = ESP_FAIL;
                } else {
                    reqResult->error = ESP_OK;
                    reqResult->result = curr->valueint;
                }
                break;
            }
            break;
        default: 
            break;
    }
    fflush(stdout);
    return ESP_OK;
}