I'm trying to connect to my bluetooth device, however upon connecting and discovering all services and characteristics, I'm unable to advance because the information returned is insufficient. I receive no service UUIDs nor any characteristic UUIDs.
What do I need to do to be able to access the UUIDs to then be able to read from the characteristics?
My device after calling device.discoverAllServicesAndCharacteristics(); returns:
{ _40: 0, _65: 0, _55: null, _72: null }
and when I log device I get:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { isConnectable: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: rssi: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: serviceData: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: overflowServiceUUIDs: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: mtu: 23,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: localName: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: manufacturerData: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: txPowerLevel: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: id: '00:1E:C0:65:D7:DB',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: solicitedServiceUUIDs: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: name: 'RND7DB',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: serviceUUIDs: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _manager:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _eventEmitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriptionsForType:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { appStateDidChange:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: isAvailable: true,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _eventHandlers: { change: {}, memoryWarning: {} },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: currentState: 'active' },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'appStateDidChange',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: websocketMessage: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: websocketOpen: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: websocketClosed: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: websocketFailed: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: didUpdateDimensions:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _currentSubscription: null },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'didUpdateDimensions',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: hardwareBackPress:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _currentSubscription: null },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'hardwareBackPress',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: collectBugExtraData:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _currentSubscription: null },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function: collectExtraData],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'collectBugExtraData',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: collectRedBoxExtraData:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _currentSubscription: null },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function: collectExtraData],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: null,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'collectRedBoxExtraData',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: url:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter: { _subscriber: [Circular] },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'url',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter: { _subscriber: [Circular] },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'url',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 1 } ],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: toggleElementInspector:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: [ { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: _currentSubscription: null },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: listener: [Function],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: context: undefined,
06-23 16:36:54.758 4397 4597 I ReactNativeJS: eventType: 'toggleElementInspector',
06-23 16:36:54.758 4397 4597 I ReactNativeJS: key: 0 },
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: emitter:
06-23 16:36:54.758 4397 4597 I ReactNativeJS: { _subscriber: [Circular],
06-23 16:36:54.758 4397 4597 I ReactNativeJS: sharedSubscribe
At this point, I do not know what to do as I have received no valuable information to further get information from a characteristic.
According to the docs, I need the UUIDs to read from my device.
device.readCharacteristicForService(
serviceUUID: UUID,
characteristicUUID: UUID,
transactionId: ?TransactionId
): Promise<Characteristic>
Note: When I use Ble Scanner app on android, I'm able to receive all services and characteristics with their UUIDs.
@action connect = (deviceName) => {
const device = this.devices.find(device=>device.name === deviceName);
if(device === undefined){
this.info = "Couldn't find device";
return;
}
this.manager.stopDeviceScan();
this.selectedDevice = device;
this.selectedDevice
.connect()
.then((device) => {
this.info = "Discovering services and characteristics";
return device.discoverAllServicesAndCharacteristics();
})
.then((device) => {
this.info = "Setting notifications";
return this.setupNotifications(device)
})
.then(() => {
this.info = "Listening..."
}, (error) => {
this.info = error.message;
})
};
async setupNotifications(device) {
console.log(device);
console.log(this.manager.servicesForDevice(device.id));
}
Here’s how I use it, hope it could help
const { updateCharacteristic } = this.props
const connectedDevice = await manager.connectToDevice(device.id)
const services = await connectedDevice.discoverAllServicesAndCharacteristics()
const characteristic = await this.getServicesAndCharacteristics(services)
getServicesAndCharacteristics(device) {
return new Promise((resolve, reject) => {
device.services().then(services => {
const characteristics = []
services.forEach((service, i) => {
service.characteristics().then(c => {
characteristics.push(c)
if (i === services.length - 1) {
const temp = characteristics.reduce(
(acc, current) => {
return [...acc, ...current]
},
[]
)
const dialog = temp.find(
characteristic =>
characteristic.isWritableWithoutResponse
)
if (!dialog) {
reject('No writable characteristic')
}
resolve(dialog)
}
})
})
})
})
}
Best regards.