BLEdescriptor readValue() gives an error indicating UUID of characteristic not the descriptor

Developers
1

I need to read a value using a BLE Descriptor (readValue). But it returns a not found condition in an app, but it does not in the devtools. I know devtools is using another API.

Anyone used this BleDescriptor - Homey Apps SDK v3 call in an app and got a result?

Code snippet of the used code… it finds the BLEDescriptor, then the readValue gives an error

Descriptor Not Found: 0000004f0000100080000026bb765291 which is the UUID of the BLEcharacteristic, not the UUID of the BLEdescriptor.

        const characteristicInstanceIdUuid = BLEUtils.uuidToNobleUuid(BLEConstants.CharacteristicInstanceIdUuid);

        try {
            if (!this.peripheral.isConnected) await this.peripheral.connect();
            const descriptors = await characteristic.discoverDescriptors();
            const descriptor = descriptors.find((d) => {
                return d.uuid === characteristicInstanceIdUuid;
            });

            this.homey.log('Found IID descriptor for', descriptors.length, descriptor);
            const data = await descriptor.readValue();
            this.homey.log('Read IID', data.readUInt16LE(0));

            return data.readUInt16LE(0);
        } catch (err) {
            this.homey.error('Error getting IID', err);
            throw err;
        }
2

That seems almost identical to this issue that I reported:

But in that case it was “Characteristic not found” instead of “Descriptor not found”

4

Well… i will need subscribetonotifications as well after this works… it works in the WebAPI that is running devtools, so it can be made to work if Athom repairs the code…

5

Yes, same with me. Works in Developer Tools but not when calling it from the Homey app