ESP32 BLE not working

Greetings,

I have tried out the beta example of ESP32 BLE communication and it seems it is no longer working. The serial output on the ESP32 side shows that the connection is made, but the Blynk app shows no connection. Inspection done with a generic BLE app allows me to connect with ESP32 with the attribute/access 0x1801/0x1800, but the service is shown as unknown.

Maybe this is due to changes to the BLE ESP32 Arduino library?

I cannot reproduce your problem. In my case everything works perfect:

  • ESP32 board version 1.0.4, board = ESP32 Dev Module
  • Blynk library 0.6.1
  • (Android) Blynk app version 5/12/2019
  • Example code Blynk ESP32_BLE
    I just need to wait 10 seconds when first connecting.

Please specify

  • ESP32 Arduino board library version & selected hardware
  • Blynk library version
  • OS of app & version
  • run the ESP32 BLE example code with
    #define BLYNK_DEBUG
    added.

ESP board version: 1.0.4 board = LOLIN32
Blynk library 0.6.1
Andriod Blynk app 5/12/2019
Example code Blynk/ESP32_BLE with the changed credentials.
#define BLYNK_DEBUG added

The board and the BLE library are otherwise is working fine, when I use another sketch to connect to a BLE app, it works OK. The example sketch shows in the serial interface ‘Waiting for connections’ and the Blynk ASCII logo, then stops.

Only when I probe it with a generic BLE app it shows connection logs.

It looks a problem on Android. In recent Android versions, a common cause is that the location permission needs to be enabled for BLE.

Remark that there is an alternative: use Bluetooth classic, which is a more stable communication protocol, also possible on ESP32+Android+Blynk