pub unsafe extern "C" fn esp_now_register_recv_cb(
    cb: esp_now_recv_cb_t
) -> esp_err_t
Expand description

@brief Register callback function of receiving ESPNOW data

@param cb callback function of receiving ESPNOW data

@return - ESP_OK : succeed - ESP_ERR_ESPNOW_NOT_INIT : ESPNOW is not initialized - ESP_ERR_ESPNOW_INTERNAL : internal error