This is not easy to accomplish and unfortunately Thunkable does not scan available UUIDs for read/write
Let me explain a bit here, BLE devices should have a minimum of 4 UUID numbers.
- a UUID for the device itself. This is the one you will see when you scan devices.
- a UUID for the service. Thunkable does not use it nor show it.
- a UUID to send data this is called characteristic UUID. This is required by Thunkable but unfortunately there is no way to scan it within Thunkable.
- a UUID to receive data this is called characteristic UUID. This is required by Thunkable but unfortunately there is no way to scan it within Thunkable.
You need a tool to show you the characteristic UUID for send/receive to be able to use them.
What makes it even more complicated, there are many BLE devices that provides more than one service and provide more than UUID service and under each service you might see a list of characteristic UUIDs not just one or two.
See example from the scanning tool