(solved) esp_event_loop_create_default() returned ESP_ERR_INVALID_STATE

[mzimmers]

Hi all -

Trying to write an initialization routine...starts like this:

Code: Select all

esp_err_t wifiInit(wifi_mode_t mode) {
    esp_err_t err = ESP_OK;
    do {
        // step 1 in https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/wifi.html:
        // Wifi/LwIP Init.
        // step 1.1: call esp_netif_init()
        err = esp_netif_init();
        if (err != ESP_OK) {
            ESP_LOGE(TAG, "wifiInit(): esp_netif_init() returned \"%s\".", esp_err_to_name(err));
            continue;
        }

        // step 1.2 
        // identify the event handler.
        err = esp_event_loop_create_default();
        if (err != ESP_OK) {
            ESP_LOGE(TAG, "wifiInit(): esp_event_loop_create_default() returned \"%s\".", esp_err_to_name(err));
            continue;
        }

And the call to esp_event_loop_create_default() returns ESP_ERR_INVALID_STATE.

What state is the error message referring to? And, what could be causing this so early in the routine?

Thanks...

[boarchuz]

Probably because it's already initialised. Many components depend on the event loop being initialised, so you should do it once early in your main initialisation. Repeated calls will return ESP_ERR_INVALID_STATE.

Is there another esp_event_loop_create_default() somewhere before this wifiInit()?

[mzimmers]

Hi boarchuz - that was the problem. I had one call, but it was in a routine that was repeated. Thanks for the help.

[leschge]

This behavior is not documented in the reference, and it should be declared what cause this error raises. (Probably because it's already initialised. )
https://docs.espressif.com/projects/esp ... e_defaultv

[HPekiM]

Is there any means to detect if "esp_event_loop_create_default()" was already called before? Or do I have to keep track of that call on my own?

Thanks in advance
Mike

[mzimmers]

Well, you could use the return from the call.