app/org.scottishtecharmy.soundscape.bluetooth/AudioHeadsetBatteryMonitor

AudioHeadsetBatteryMonitor

class AudioHeadsetBatteryMonitor(context: Context)

Reports battery level (0–100) for the most recently active Bluetooth audio device, using the system broadcast Android fires when it learns a connected headset's battery (via HFP AT+IPHONEACCEV, AVRCP GetCapabilities, or vendor profiles).

The broadcast action and extra strings are hidden BluetoothDevice constants but have been stable for years — every music player on Android relies on them. They're protected broadcasts so only the system can send them.

Limitations:

Only fires for paired audio devices, not arbitrary BLE peripherals.
AirPods on Android typically don't report battery (Apple's protocol isn't parsed by the AOSP stack).
Requires the BLUETOOTH_CONNECT runtime permission on API 31+.

Constructors

AudioHeadsetBatteryMonitor

constructor(context: Context)

Types

Companion

object Companion

Properties

batteryPercentFlow

val batteryPercentFlow: StateFlow<Int?>

0–100, or null until the first audio device reports.

Functions

start

fun start()

stop

fun stop()