iOS - Not receiving call back when enabling startNotifications

[rudreshHestabit]

Describe the bug

1. I am not receiving the callback after start notification in iOS code. 2)Some times when I tried to write values I am getting Unlikely error

To Reproduce Steps to reproduce the behavior:

1. connect device
2. write value to characteristics
3. startNotifications() with iOS side
4. observe that we are not getting callback response.

Expected behavior I need callback from iOS side android I am getting response but iOS not Reference Code:

    await BleClient.initialize()
    console.log("Here we are")
    const res = await BleClient.requestDevice()
    console.log("--> res",JSON.stringify(res))      
            
    await BleClient.connect(res.deviceId) 

    await BleClient.write(res.deviceId, SERVICE, CHARACTERISTIC, numbersToDataView([0x01, 0x00]), 15000)
    await BleClient.startNotifications(
      res.deviceId,
      SERVICE,
      CHARACTERISTIC,
      (value) => {
        console.log("+++++++++++Notification call back++++++++++")
        this.notifyBLE(value)
      },
    )

Plugin version: "@capacitor-community/bluetooth-le": "^1.8.2. and I tried with 1.4.0

**LOGs

dataWrite 2 bytes Resolvevalue write|197A1398-719D-48CF-87C2-4D0535CB48B1|10E0C266-B3F3-4FB5-A0DF-3B1570BE06E8 Successfully written value. ⚡️ TO JS undefined ⚡️ To Native -> BluetoothLe removeListener 821728 ⚡️ To Native -> BluetoothLe addListener 821729 ⚡️ To Native -> BluetoothLe startNotifications 821730 notifyCallback Set notifications true Reject callback not registered for key: write|197A1398-719D-48CF-87C2-4D0535CB48B1|10E0C266-B3F3-4FB5-A0DF-3B1570BE06E8 Resolve setNotifications|197A1398-719D-48CF-87C2-4D0535CB48B1|10E0C266-B3F3-4FB5-A0DF-3B1570BE06E8 Successfully set notifications.

[pwespi]

Unfortunately I cannot reproduce this. Does it happen all the time or just some times? Have you tried different iOS devices?

[rudreshHestabit]

this is the swift code bridging inbuilt in plugin, however

1. with commenting this code ---- writing is possible, not getting notification response
2. without commenting this code ---- writing is not happening,

func write(_ serviceUUID: CBUUID, _ characteristicUUID: CBUUID, _ value: String, _ writeType: CBCharacteristicWriteType, _ callback: @escaping Callback) { let key = "write|(serviceUUID.uuidString)|(characteristicUUID.uuidString)" self.callbackMap[key] = callback guard let characteristic = self.getCharacteristic(serviceUUID, characteristicUUID) else { self.reject(key, "Characteristic not found.") return } if value == "" { self.reject(key, "Invalid data.") return } let data: Data = stringToData(value) self.peripheral.writeValue(data, for: characteristic, type: writeType) // if writeType == CBCharacteristicWriteType.withResponse { // self.setTimeout(key, "Write timeout.") // } else { // self.resolve(key, "Successfully written value.") // } self.resolve(key, "Successfully written value.") }``

[rudreshHestabit]

@pwespi
1 In your native plugin swift code I can not able to write characteristics in iOS 12 2 if writeType == CBCharacteristicWriteType.withResponse when I comment this part of the code I can able to write the values and not getting the response callback from startNotification please help us

[Deval99]

Everything is working fine in android, but in iOS, device stops receiving notification response after calling BleClient.getConnectedDevices(),

and everytime it is throwing error, "Resolve callback not registered for key: ...." But when BleClient.getConnectedDevices() is not called, it is still working.

I have tried to remove BleClient.getConnectedDevices() from whole project, the app is working fine in iOS.

LOGS : `⚡️ To Native -> BluetoothLe addListener 80124203 ⚡️ To Native -> BluetoothLe startNotifications 80124204 . . . Resolve setNotifications|<SERVICE_ID>|<B7__UUID> Successfully set notifications. ⚡️ TO JS undefined

Resolve callback not registered for key: read|<SERVICE_ID>|<B7__UUID> ⚡️ TO JS {"value":"ba 00 00 04 01 00 00 "} . . // RECEIVED A NOTIFICATION HERE . . . . // Now main culprit //------------------- ⚡️ To Native -> BluetoothLe getConnectedDevices 80124205 ⚡️ TO JS {"devices":[{"deviceId":"-------","name":"--------"}]} //------------------- . . . . . ⚡️ To Native -> BluetoothLe read 80124206 Resolve read|<SERVICE_ID>|<7E__UUID> 00 00 00 00 b7 ae 00 00 32 b7 00 cc 00 2f 00 00 ⚡️ TO JS {"value":"00 00 00 00 b7 ae 00 00 32 b7 00 cc 00 2f 00 00 "} . . . . .

⚡️ To Native -> BluetoothLe write 80124207 Resolve write|<SERVICE_ID>|<C7__UUID> Successfully written value. ⚡️ TO JS undefined

Resolve callback not registered for key: read|<SERVICE_ID>|<B7__UUID> . . . . .

// FAILS TO GIVE NOTIFICATION HERE

. . . 3 seconds time gap . . .

⚡️ To Native -> BluetoothLe stopLEScan 80124208 Stop scanning.

⚡️ TO JS undefined`

[pwespi]

There is a known issue that notifications stop working after getConnectedDevices see https://github.com/capacitor-community/bluetooth-le/issues/460.

Without using getConnectedDevices, is the issue described here still happening?

[bitforcesrl]

i've spent HOURS of debugging trying to figure out which was the problem of notifications not receive, and it was the getConnectedDevices call. We use this method because some times on live reload the app is reloading but the device is still connected to the phone and if we click connect again we have some issue. Then we have multiple devices that can be connected to the phone and we need to get the list of them I think that this is an utility that should be fixed

[pwespi]

Version 2.2.1 contains a fix for a bug where getConnectedDevices or getDevices stopped existing notifications.

Is the original issue described here still happening in 2.2.1?

[bitforcesrl]

@pwespi it's fixed in this version 2.2.1 Thanks!!!!

[github-actions[bot]]

It looks like this issue didn't get the information it needed, so I'll close it for now. If I made a mistake, sorry! I am just a bot.

Have a great day! Capacitor Community Bot 💙