Speed & Cadence Sensor Connection

Hi All, I try to connect a Speed & Cadence Sensor with UUID “00002A5B-0000-1000-8000-00805F9B34FB” all I get is a “Operation Rejected”

I can connect to the sensor and try to receive byte array but get “Operation Rejected” do I something wrong or is this not possible with Thunkable? I have this working in Unity3D but like to build it with Thunkable.

Thx! Roy

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are you connecting to the device first? The image below is how I connect. to one of my own BLE devices.

Screen Shot 2022-05-25 at 10.59.17 AM

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This will not work. Your device has only NOTIFY property in this UUID and you are trying to do a READ operation. So Operation Failed is a logical response. You need the READ property to do this.

Currently Thunkable does not listen to NOTIFY channels.

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Hi Muneer, Thanks for your answer. Notification doesn’t need to be acknowledged, so they are faster and an efficient way to read data continuously, Hope this will be supported but think this will be a long wait.

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I hope so.

In the classic Bluetooth connection, Read & Write can only take place after connecting (pairing) with the Bluetooth device. But this has a downside because Bluetooth devices allow only one single pairing at any one time.

The answer was with BLE notification which does not require pairing but rather Subscribing to the service.

Let’s hope Thunkable will introduce subscription to BLE devices (services).


Does anyone know about update of this?
Its a highly requested functionality.
I dont understand why in Thunkable BLE only can work with Read Characteristic but it can not Subscribe to Notify Characteristic.