IssueTracker

1. Problem Description:

When using a BLE devices like the Logitech MX keyboard or mouse that broadcasts its battery percentage using the Bluetooth SIG-standardized Battery Service (0x180F) and Battery Level Characteristic (0x2A19), the battery information is not displayed in the Android system UI (e.g., settings or widgets).

2. Steps to Reproduce:

1. Connect a BLE device that implements the Battery Service (0x180F) and Battery Level Characteristic (0x2A19) to an Android device.
2. Verify that the device is correctly broadcasting the battery percentage using a BLE debugging tool (e.g., nRF Connect or LightBlue).
3. Check the Android system settings > bluetooth settings, search for battery information related to the connected BLE device.

3. What Happened:

• The battery percentage is not displayed in the Android system UI (settings or widgets) for the connected BLE device.
• This behavior is consistent across multiple devices, including the Logitech MX keyboard and mouse, which also use the same standard.

4. Expected Behavior:

• The Android system UI should display the battery percentage for BLE devices that comply with the Bluetooth SIG-standardized Battery Service (0x180F) and Battery Level Characteristic (0x2A19).
• This would align with the behavior seen for other device types (e.g., Bluetooth headphones or wearables) that display battery information in the system UI.

5. Is This a Security-Related Issue?

• No, this is not a security-related issue. It is a functional issue related to the display of battery information in the system UI.

6. Android Version and Device Information:

• Android Version: Android 15
• Device Model: Nothing Phone (2)
• BLE Device: Logitech MX Master 3 mouse

8. Sample Code (if applicable):

For example this code can gather battery info:

package com.example.blebattery

import android.Manifest.permission.BLUETOOTH_CONNECT
import android.annotation.SuppressLint
import android.bluetooth.BluetoothDevice
import android.bluetooth.BluetoothGatt
import android.bluetooth.BluetoothGattCallback
import android.bluetooth.BluetoothGattCharacteristic
import android.bluetooth.BluetoothManager
import android.bluetooth.BluetoothProfile
import android.content.Context
import android.content.Context.BLUETOOTH_SERVICE
import android.content.pm.PackageManager.PERMISSION_GRANTED
import android.os.Bundle
import android.util.Log
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat.checkSelfPermission
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import java.lang.Thread.sleep
import java.util.UUID

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val adapter = (getSystemService(BLUETOOTH_SERVICE) as BluetoothManager?)?.adapter
        if (checkSelfPermission(this, BLUETOOTH_CONNECT) == PERMISSION_GRANTED) {
            val device = adapter?.bondedDevices.orEmpty().first { it.name == "MX Master 3" }
            device.connectGatt(this, true, CustomBluetoothGattCallback)
            while (true) {
                CustomBluetoothGattCallback.readCharacteristic()
                sleep(5000)
            }
        } else {
            Log.i(TAG, "Request permission")
        }
    }
}

@SuppressLint("MissingPermission")
object CustomBluetoothGattCallback : BluetoothGattCallback() {

    private val Battery_Service_UUID: UUID = UUID.fromString("0000180F-0000-1000-8000-00805f9b34fb")
    private val Battery_Level_UUID: UUID = UUID.fromString("00002a19-0000-1000-8000-00805f9b34fb")
    private var gatt: BluetoothGatt? = null
    private var characteristic: BluetoothGattCharacteristic? = null
    fun readCharacteristic() {
        gatt?.readCharacteristic(characteristic)
    }
    override fun onConnectionStateChange(gatt: BluetoothGatt, status: Int, newState: Int) {
        if (newState == STATE_CONNECTED) {
            Log.i(TAG, "Connected to device!")
            this.gatt = gatt
            gatt.discoverServices()
        }
    }

    override fun onServicesDiscovered(gatt: BluetoothGatt, status: Int) {
        if (status == GATT_SUCCESS) {
            gatt.getService(Battery_Service_UUID)?.let { service ->
                service.getCharacteristic(Battery_Level_UUID)?.let { characteristic ->
                    this.characteristic = characteristic
                    gatt.readCharacteristic(characteristic)
                }
            }
        }
    }

    override fun onCharacteristicRead(
        gatt: BluetoothGatt,
        characteristic: BluetoothGattCharacteristic,
        value: ByteArray,
        status: Int
    ) {
        val batteryLevel = value[0]
            .toInt()
            .and(0xFF)
        Log.d(TAG, "onCharacteristicRead: $batteryLevel %")
    }
}

9. Disclaimer Acknowledgment:

By submitting this bug report, I acknowledge that Google may use the information included in the report to diagnose technical issues and improve its products and services, in accordance with its Privacy Policy. I also agree that Google may share this information with engineering partners potentially impacted by the issue.