This document discusses using Arduino and the Google Android Open Accessory Development Kit (ADK) to connect Android devices to hardware. It provides an overview of Arduino, describes the Google ADK and how it allows an Android device to communicate over USB with an Arduino board. It also outlines the steps to write firmware for the Arduino, create an Android application, and provides examples of uses including a sonar demo and motor control demo.

1. Smartphone++
Marc Lester S. Tan
Mobile Applications Developer, SAP
GDG Devfest Kota Kinabalu 2013

2. Agenda
● Overview of Arduino
● Google ADK
● Uses of ADK and Demo

3. Overview of Arduino

4. Overview of Arduino
•
Open-source electronics prototyping
platform.
•
Intended for Artists, Designers and
Hobbyists.
•
Arduino Programming Language based
on Wiring.
•
Arduino IDE based on Processing
source: http://www.arduino.cc

5. Overview of Arduino
•
Inexpensive
•
Cross-platform
•
Simple and clear programming environment.
•
Open-source software and hardware

6. Arduino Shields
Shields are boards that can be plugged on top
of the Arduino PCB extending its capabilities.
•
SD Card Shield
•
USB Host Shield
•
Ethernet Shield
source:
http://blog.protoneer.co.nz/

7. Arduino IDE
•
Java
•
Based on Processing IDE
(processing.org)
•
Write and upload code to Arduino
board

8. Arduino Sketch
•
setup()
o called once
o setup pin modes
o library initialization
•
loop()
o called over the over again
o heart of every sketches

9. Sample Sketch
int inputPin = 12;
// let pin 12 be our input pin
int outputPin = 11;
// let pin 11 be our ouput pin
void setup(){
pinMode(outputPin, OUTPUT);
// setup output pin to be an OUTPUT
pinMode(inputPin, INPUT);
// setup input pin to be our INPUT
}
void loop(){
int inputVal = digitalRead(inputPin);
digitalWrite(outputPin, inputVal);
delay(100);
}
// write the value of input pin to output
// wait for 100ms
// before looping again.

10. Google ADK

11. USB on Android
Host Mode
Power
Data Transfer
Accessory Mode
Power
Data Transfer

12. Google ADK
● Reference implementation for
hardware manufacturers and
hobbyists.
● It uses Android Open Accessory
Protocol over USB or Bluetooth
● The hardware is based on
Arduino Mega.
● Two versions: ADK 2011 and
ADK 2012
source: http://www.engadget.com/gallery/googles-arduino-based-adk-hands-on-atgoogle-i-o-2011/

13. Hello, Physical World
•
Design and create the hardware or
circuit.
•
Write the firmware for your
Arduino.
•
Create an Android application that
can talk to your firmware.
source: http://www.youtube.com/watch?v=gcP7KwIENGw

14. Design and Create the Hardware
•
Use Fritzing to design your
breadboard, schematic diagram
and bill of materials.
•
Get it from http://fritzing.org/

15. Write the Firmware
if (acc.isConnected()) {
int len = acc.read(msg, sizeof(msg), 1);
if(len > 0){
Serial.println(len);
if(msg[0] == 0x1){
digitalWrite(13, HIGH);
}else{
digitalWrite(13, LOW);
}
}
}else{
digitalWrite(13, LOW);
}

16. Create the Android Application
●
USBManager - available since 3.1 but also available for 2.3.4 using Google API 10
○
●
Not all devices support accessory mode
Android Manifest Requirements:
Declare:
<uses-feature android:name="android.hardware.usb.accessory" />
If using Add-on:
<application….>
<uses-library android:name="com.android.future.usb.accessory" />

17. Create the Android Application
Android Manifest Requirements:
<activity ...>
...
<intent-filter>
<action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" /
>
</intent-filter>
<meta-data android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED"
android:resource="@xml/accessory_filter" />
</activity>

18. Create the Android Application
res/xml/accessory_filter.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<usb-accessory manufacturer="Marc Tan" model="Motor Control" version="1.0" />
</resources>

19. Create the Android Application
onCreate()...
mUsbManager = UsbManager.getInstance(this);
onResume()...
UsbAccessory[] accessories = mUsbManager.getAccessoryList();
UsbAccessory accessory = accessories[0]);
if (mUsbManager.hasPermission(accessory)) {
openAccessory(accessory);
}

20. Create the Android Application
protected void openAccessory(UsbAccessory accessory) {
fileDescriptor = mUsbManager.openAccessory(accessory);
FileDescriptor fd = fileDescriptor.getFileDescriptor();
input = new FileInputStream(fd);
output = new FileOutputStream(fd);
}
onDestroy()...
output.write(0); // optional
fileDescriptor.close();

21. Uses of ADK and Demo

22. Uses of ADK
Audio Docking Station

23. Uses of ADK
Exercise Machines

24. Uses of ADK
Weather Stations

25. Uses of ADK
Home Automation

26. Demo: Sonar

27. Demo: Motor Control

28. Demo: Android as USB Host

29. Resources
Android ADK
a.android.com
Arduino and Electronics, Others
arduino.cc
tronixstuff.com
hackaday.com
My Blog and Github
marctan.com
github.com/mharkus
Quadcopter
bitcraze.se

30. Thank you
Questions?