- 1 year ago
Battery Level of Bluetooth devices using Java
To retrieve the battery level of Bluetooth devices using Java, you can utilize the BluetoothGatt API available in Android. Here's an example of how you can retrieve the battery level:
javaimport android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.os.Bundle;
public class BluetoothBatteryLevel {
private BluetoothGatt bluetoothGatt;
public void retrieveBatteryLevel(Context context, BluetoothDevice device) {
BluetoothManager bluetoothManager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
bluetoothGatt = device.connectGatt(context, false, gattCallback);
}
private final BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
super.onConnectionStateChange(gatt, status, newState);
if (newState == BluetoothGatt.STATE_CONNECTED) {
gatt.discoverServices();
} else if (newState == BluetoothGatt.STATE_DISCONNECTED) {
// Handle disconnection
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
super.onServicesDiscovered(gatt, status);
if (status == BluetoothGatt.GATT_SUCCESS) {
BluetoothGattService batteryService = gatt.getService(BatteryServiceUuid);
BluetoothGattCharacteristic batteryLevelCharacteristic = batteryService.getCharacteristic(BatteryLevelCharacteristicUuid);
gatt.readCharacteristic(batteryLevelCharacteristic);
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
super.onCharacteristicRead(gatt, characteristic, status);
if (status == BluetoothGatt.GATT_SUCCESS) {
if (BatteryLevelCharacteristicUuid.equals(characteristic.getUuid())) {
int batteryLevel = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT8, 0);
// Use the battery level value
Bundle result = new Bundle();
result.putInt("batteryLevel", batteryLevel);
// Pass the result to your UI or further processing
}
}
gatt.disconnect();
gatt.close();
}
};
// UUIDs of the Battery Service and Battery Level Characteristic
private static final String BatteryServiceUuid = "0000180f-0000-1000-8000-00805f9b34fb";
private static final String BatteryLevelCharacteristicUuid = "00002a19-0000-1000-8000-00805f9b34fb";
}
In this example, the retrieveBatteryLevel
method accepts a Context
object and a BluetoothDevice
object. It uses the BluetoothManager
to obtain a BluetoothGatt
instance for the device and establishes a GATT connection.
The BluetoothGattCallback
is implemented to handle connection state changes, service discovery, and characteristic reading. When the connection state changes to STATE_CONNECTED
, it triggers service discovery. Once services are discovered (onServicesDiscovered
), it retrieves the battery service and battery level characteristic based on their UUIDs. Finally, the battery level is read from the characteristic (onCharacteristicRead
), and the connection is closed.
Make sure to adjust the UUIDs (BatteryServiceUuid
and BatteryLevelCharacteristicUuid
) according to the specific Bluetooth device you are working with. Additionally, you may need to handle errors and timeouts appropriately in your implementation.
Note that this example is for Android, utilizing the Android BluetoothGatt API. The approach may differ for other