driver-hcsr04

HC-SR04 ultrasonic ranging module driver for Android Things

This driver supports the HC-SR04 ultrasonic ranging module.

NOTE: these drivers are not production-ready. They are offered as sample implementations of Android Things user space drivers for common peripherals as part of the Developer Preview release. There is no guarantee of correctness, completeness or robustness.

This driver is based on the AndroidThings-UltrasonicSensor from Danesz.

How to use the driver

Gradle dependency

To use the hcsr04 driver, simply add the line below to your project's build.gradle, where <version> matches the last version of the driver available on jcenter.

dependencies {
    implementation 'com.leinardi.android.things:driver-hcsr04:<version>'
}

Sample usage

public class DistanceActivity extends Activity implements SensorEventListener {
    private static final String TAG = DistanceActivity.class.getSimpleName();

    private Hcsr04SensorDriver mProximitySensorDriver;
    private SensorManager mSensorManager;

    private SensorManager.DynamicSensorCallback mDynamicSensorCallback = new SensorManager
            .DynamicSensorCallback() {
        @Override
        public void onDynamicSensorConnected(Sensor sensor) {
            if (sensor.getType() == Sensor.TYPE_PROXIMITY) {
                mSensorManager.registerListener(DistanceActivity.this,
                        sensor, SensorManager.SENSOR_DELAY_NORMAL);
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mSensorManager.registerDynamicSensorCallback(mDynamicSensorCallback);

        try {
            mProximitySensorDriver = new Hcsr04SensorDriver(trigPin, echoPin);
            mProximitySensorDriver.registerProximitySensor();
        } catch (IOException e) {
            // couldn't configure the device...
        }

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mProximitySensorDriver != null) {
            mSensorManager.unregisterDynamicSensorCallback(mDynamicSensorCallback);
            mSensorManager.unregisterListener(this);
            mProximitySensorDriver.unregisterProximitySensor();
            try {
                mProximitySensorDriver.close();
            } catch (IOException e) {
                // error closing sensor
            } finally {
                mProximitySensorDriver = null;
            }
        }
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        Log.i(TAG, String.format(Locale.getDefault(), "sensor changed: [%f]", event.values[0]));
    }

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

License

Copyright 2018 Roberto Leinardi

Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.