BLE Characteristic UUID issue for BatteryLevel

[didier.coymanohatdl]

I am using an ESP32 to publish some telemetry. Using the GATT specification, I try to connect to the characteristic UUID 2A19 published by the ESP32 without success. I get a “Can’t read characteristic provided.” I can see it and I can read it using the RF Connect app. As per the bluetooth specification the characteristic is READ, NOTIFY.
I tried the connect to 2A19 or 00000000-0000-0000-0000-000000002A19, no difference.

Connecting to a generated UUID and read other characteristics works fine. Any idea why the official UUID for BatteryLevel can’t be read?

[didier.coymanohatdl]

[matt_conroy]

@didier.coymanohatdl If the documentation only gives four characters for the value, they are assuming you’ll use the default characterstic UUID.

It is discussed more in this previous topic.

Trying to connect Bluetooth BP cuff, but struggling with the "characteristic UUID" stuff

This is the default or base UUID for all characteristic IDs if not set by the factory. The default is 00000000-0000-1000-8000-00805F9B34FB If the manufacturer is giving you only 4 digit then it is assumed that you need to use the default UUID. It starts with 8 hexadecimal digits and you need to add your 4 digit hexadecimal number as the second part of it. So instead of all zeros it would be 0000 plus your code FFF4

[didier.coymanohatdl]

It did indeed fix the issue, Thank you so much.