Get last ambient temperature from android device with temperature sensor.

SensorActivity.kt

public class SensorActivity extends Activity implements SensorEventListener {
    private final SensorManager mSensorManager;
    private final Sensor mTempSensor;
    
    private float lastTemperature= 0F

    public SensorActivity() {
        mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
        mTempSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_AMBIENT_TEMPERATURE);
    }

    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, mTempSensor, SensorManager.SENSOR_DELAY_NORMAL);
    }

    protected void onPause() {
        super.onPause();
        mSensorManager.unregisterListener(this);
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {}

    public void onSensorChanged(SensorEvent event) {
        lastTemperature=event.values[0];
    }
}