Native Peripheral I/O

This Android Things app runs basic code that exercises the Native PIO APIs from C++. Each sample is an Android module that can be run independently.

Note: The Android Things Console will be turned down for non-commercial use on January 5, 2022. For more details, see the FAQ page.

Screenshots

Blink

(Watch the demo on YouTube)

Button

(Watch the demo on YouTube)

Speaker

(Watch the demo on YouTube)

Pre-requisites

• Android Things compatible board
• Android Studio 2.2+
• Android NDK bundle

For the Blink sample:

• 1 LED
• 1 resistor
• 2 jumper wires
• 1 breadboard

For the Button sample:

• 1 push button
• 1 resistor
• 2 jumper wires
• 1 breadboard

For the Speaker sample:

• 1 piezo buzzer
• 2 jumper wires
• 1 breadboard

Build and install

Download the latest Android Things native library release and extract it in the project root directory. You will need to change the name of the extracted directory to libandroidthings.

The project root directory should contain the following native library directories:

libandroidthings/
  ${ABI}/
    include/
      pio/
        *.h
    lib/
      libandroidthings.so

On Android Studio, select the module in the select box by the "Run" button, and then click on the "Run" button.

If you prefer to run on the command line, type

./gradlew <module>:installDebug
adb shell am start com.example.androidthings.nativepio/.<ModuleActivity>

Sample Specifics

Blink

    ./gradlew blink:installDebug
    adb shell am start com.example.androidthings.nativepio/android.app.NativeActivity

Blinks an LED connected to a GPIO pin.

Button

    ./gradlew button:installDebug
    adb shell am start com.example.androidthings.nativepio/android.app.NativeActivity

Logs to logcat when a button connected to a GPIO pin is pressed. Make sure you use a pull-down or pull-up resistor to avoid fluctuation.

Speaker

    ./gradlew speaker:installDebug
    adb shell am start com.example.androidthings.nativepio/android.app.NativeActivity

Plays an annoying alarm sound on the PWM speaker. Stop it by turning off the Raspberry Pi.

Enable auto-launch behavior

This sample app is currently configured to launch only when deployed from your development machine. To enable the main activity to launch automatically on boot, add the following intent-filter to the app's manifest file:

<activity ...>

    <intent-filter>
        <action android:name="android.intent.action.MAIN"/>
        <category android:name="android.intent.category.HOME"/>
        <category android:name="android.intent.category.DEFAULT"/>
    </intent-filter>

</activity>

License

Copyright 2016 The Android Open Source Project, Inc.

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.