Create a BLE app for your mobile phone! Control an ESP32 with BLE

Summary:
In this video I show you how to create your own Bluetooth Low Energy (BLE) App to control an ESP32 (Arduino platform). For creation of the app I use the MIT app inventor in combination with the MIT AI2 Companion. I have tested this on an Android phone. I have heard in the meantime that unfortunately MIT App Inventor does not support BLE for the Iphone yet. Please make sure your ESP32 has Bluetooth to make this work. Note that some older ESP32 will not work with MIT App Inventor.

Confirmed to work on:
ESP32-WROOM-32D
ESP32-WROOM-32 (Mini D1 ESP32)

Does not work on (will not connect):
ESP32-WROOM-32 (some of the older versions)

NOTE: In order for the App to work as compiled .apk file, the "BluetoothClient" element needs to be added to the MIT App Inventor project (can be found in the "Connectivity" section). I forgot to mention this in the video.

Starting point for coding along for the Arduino is:
https://github.com/mo-thunderz/Esp32B...

Final code:
https://github.com/mo-thunderz/BleMob...

MIT App Inventor:
https://appinventor.mit.edu/

MIT App Inventor BLE extension:
https://mit-cml.github.io/extensions/

BLE on ESP32 Tutorial:
   • BLE with ESP32 tutorial part 1: the Server  
   • BLE with ESP32 tutorial part 2: the client  

Might you have problems programming the ESP32, pls refer to:
   • Programming ESP32: how its done and issues...  

Have fun with the code and let me know in the comments below what application you are working on :-)

Correction:
6:36 Under "Connectivity" add also the "BluetoothClient" to the project. This is needed so that the app can ask for the appropriate permissions when compiled.
32:06 I mis-spoke here. The correct number to multiply the third byte with is 65536 (2^16).