Possibly:
https://docs.espressif.com/projects/esp ... p-rollback

Most likely you have memory leak in code, find it.

Just like you said, congest error means that peer device cant handle so many read/write/notify/indicate requests in short time. You can try to change connect parameter after connection: https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/bluetooth/esp_gap_ble.html#_CPPv430esp_ble_gap...

Angus, admins, support.

Is your WiFiClient::event_handler a static function?

If you are flashing this code, i am guessing it is just echoing received data: case ESP_SPP_DATA_IND_EVT: #if (SPP_SHOW_MODE == SPP_SHOW_DATA) ESP_LOGI(SPP_TAG, "ESP_SPP_DATA_IND_EVT len=%d handle=%d", param->data_ind.len, param->data_ind.handle); if (param->data_ind.len < 1023) { snprintf(buf, (siz...

It all depends how your mouse should react on moves. For example you can use only gyro to set cursor absolute position, which requires to change mouse report map just a bit, or you can use relative positioning and combine gyro + accel to calculate relative value sent as cursor move.

https://docs.espressif.com/projects/esp-idf/en/stable/api-reference/bluetooth/esp_gap_bt.html#_CPPv418esp_bt_gap_set_pin17esp_bt_pin_type_t7uint8_t17esp_bt_pin_code_t https://github.com/espressif/esp-idf/blob/6517c5033aab27afe491e433d6beeba93dfb1aa7/examples/bluetooth/bluedroid/classic_bt/bt_spp_acc...

What do you mean by read UUID?

Its because even if you turn on bluetooth on PC it wont start advertising by itself, you have to turn on advertising (its called visibility, or something like that). The same situation is with smartphones, it wont be visible as BLE device unless your application or system driver starts advertising.