Programming Objects with Android Maurizio Caporali - "Mobile & Embedded" - GDG-Firenze

1. Programming things with Android:
Home automation, Digital signage and Smart Object
using Android
Maurizio Caporali
Luca Pisani
www.udoo.org
Mobile&Embedded Firenze

2. Programming things?!?
Xerox
Alto
Douglas
Engelbart
www.udoo.org

3. Developers are changing
Programming Desktop
Computer
Programming Mobile Device
Xerox
Alto
Douglas
Engelbart
Programming Things
Prototyping Lab, FabLab, Hackathon
www.udoo.org

4. Computer Interaction is changing
Screen interaction
Xerox
Alto
Douglas
Engelbart
Interactive Things
www.udoo.org

5. www.udoo.org

6. Programming Things
It’s a complex
activity
Xerox
Alto
Douglas
Engelbart
Electronic Engineer, Mechanical Engineer, Computer
Engineer, ...
www.udoo.org

7. Programming Things: rapid prototyping tools
Arduino
*

8. Open Source
How to create the interaction
Open Source Software
Community
Xerox
Alto
Douglas
Engelbart
Linux
Android
www.udoo.org

9. Open Hardware
How to create Physical Mock Up quickly
Open Source Hardware
Community
Xerox
Alto
Douglas
Engelbart
Raspberry Pi
3D Printing
Arduino
www.udoo.org

10. Makers Revolution
Xerox
Alto
Communities
real!
Douglas
Engelbart
make this success
www.udoo.org

11. Arduino + Android: Android ADK
*

12. Applications
Ambient Devices
Home Automation
Smart Cities
Automotive
Urban Furniture
Digital Signage
Robot
*

13. What do you need?
+
Android Smartphone/Tablet
Arduino DUE
or
+
ARM single board computer
UDOO
Arduino DUE
www.udoo.org

14. What’s UDOO?
UDOO is a mini PC that could run either
Android or Linux, with an Arduinocompatible board embedded.
UDOO is a collective effort of a
multidisciplinary team spread between
North America and Europe, with expertise
in interaction design, embedded electronics
and sensor networks.
UDOO is a co-founded project by SECO
(www.seco.com) and Aidilab (www.aidilab.
com).
www.udoo.org

15. All-in-one solution
For the first time, a powerful ARM
cortex-A9 CPU for heavy tasks
with great performance, and a
dedicated ARM processor for the
GPIO are brought together in one
single board computer.
www.udoo.org

16. Arduino-compatible
UDOO is compatible with all the
sketches, tutorials and resources
available
on
the
Arduino
community as well as all the
shields, sensors and actuators for
Arduino DUE available on the
market.
www.udoo.org

17. Open Source and Community
UDOO is a proper open source
project where both hardware
designs and software are open
source.
Community development support
Schematics,
2D/3D
drawings,
Kernels and U-Boot sources are
available to the community in order
to improve and extend UDOO
capabilities and functionalities.
www.udoo.org

18. Power and flexibility for any kind of projects
www.udoo.org

19. www.udoo.org

20. Android on UDOO
Android 4.2.2 Jelly Beans runs
smoothly on UDOO giving you all
the features of an Android device.
Apps interface with Arduinocompatible
embedded
board
through Accessory Development
Kit (ADK) connection for building
accessories and smart devices
based on Android.
www.udoo.org

21. Android on UDOO
• Android Jelly Beans 4.2.2 AOSP
• up-to-date ASAP
• GAPPS could be installed: http://www.
udoo.org/guide-how-to-install-gappson-udoo-running-android/
www.udoo.org

22. Program Arduino App for UDOO
To program UDOO under Android we need the standard
tools:
● Eclipse + ADT plugin
● Android SDK Tools
● Android Platform-tools
We also need:
● Arduino IDE 1.5.4
● UDOO patch for Arduino IDE (bossac programmer)
www.udoo.org

23. UDOO Overview
● Android 4.2.2 runs on Freescale i.Mx6
(dual or quad core - 1 GB)
● UDOO is equipped with micro Atmel
SAM3X, the same of Arduino Due
● They are connected through bus USB
OTG
● We program the two CPUs separately
using Android SDK and Arduino IDE
www.udoo.org

24. UDOO Overview OTG - bus
● To allow the communication between Android and the SAM3X the
ADK protocol is needed. A set of libraries that authorize Android to
communicate with an external accessory.
● It's basically a bidirectional stream of data between the two parts
● Usually to communicate, install applications and debug the ADB
protocol is used through the USB OTG port on the android device.
● Also the microcontroller communicates using the OTG bus
www.udoo.org

25. UDOO Overview OTG - bus switch
The i.Mx6 processor can be connected with:
● the external USB port (debug app Android)
● the SAM3X microcontroller (usage)
It’s possible to switch via software between the 2 options
www.udoo.org

26. Programming Arduino
We need to program SAM3X microcontroller
with Arduino IDE downloadable from arduino.
cc
The Sketches have a standard structure, we
only need to add a library for OTG
communication.
We program the SAM3X through microUSB
serial port.
www.udoo.org

27. Programming Overview
www.udoo.org

28. AndroidManifest.xml
● Include a <uses-feature> element that declares that your
application uses the accessory feature.
<uses-feature android:name="android.hardware.usb.accessory" />
● Declare min(12) e target(17) SDK version
<uses-sdk android:minSdkVersion="15" android:targetSdkVersion="17" />
www.udoo.org

29. AndroidManifest.xml
● If you want your application to be notified of an attached USB
accessory, specify an <intent-filter> and<meta-data>
<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>
www.udoo.org

30. accessory_filter.xml
In the XML resource file, declare <usb-accessory> elements for the
accessories that you want to filter. Each<usb-accessory> can have
the following attributes:
● manufacturer
● model
● version
<?xml version="1.0" encoding="utf-8"?>
<resources>
<usb-accessory manufacturer="Aidilab" model="UDOO_ADK" version="1.0" />
</resources>
www.udoo.org

31. Activity.java
The package you need to import is android.hardware.usb. This
contain the classes to support the accessory mode
import android.hardware.usb.UsbAccessory;
import android.hardware.usb.UsbManager;
Here is a summary of the relevant code for handling USB
connections:
mUSBManager = (UsbManager) getSystemService(Context.USB_SERVICE);
...
UsbAccessory acc = (UsbAccessory)intent.getParcelableExtra(UsbManager.
EXTRA_ACCESSORY);
www.udoo.org

32. Activity.java
To explicitly obtain permission, first create a broadcast receiver. This receiver
listens for the intent that gets broadcast when you call requestPermission(). The call
to requestPermission() displays a dialog to the user asking for permission to connect
to the accessory
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbAccessory accessory = (UsbAccessory)intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);
if (intent.getBooleanExtra(
UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
openAccessory(accessory);
} else {
Log.d(TAG, "permission denied for accessory "+ accessory);
}
mPermissionRequestPending = false;
}
}
www.udoo.org

33. Activity.java
To register the broadcast receiver, put this in your onCreate()
method in your activity:
mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent
(ACTION_USB_PERMISSION), 0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);
To display the dialog that asks users for permission to connect to the
accessory, call the requestPermission() method:
mUsbManager.requestPermission(accessory,mPermissionIntent);
www.udoo.org

34. Activity.java
To communicate with the accessory you need a file descriptor to set
up input and output streams to read and write data:
private void openAccessory(UsbAccessory accessory) {
mFileDescriptor = mUsbManager.openAccessory(accessory);
if (mFileDescriptor != null) {
mAccessory = accessory;
FileDescriptor fd = mFileDescriptor.getFileDescriptor();
mInputStream = new FileInputStream(fd);
mOutputStream = new FileOutputStream(fd);
}
}
www.udoo.org

35. Activity.java
We use the output and input stream to send and receive messages to
the Arduino processors of UDOO.
byte[] message = new byte[1];
message[0] = (byte)1;
mOutputStream.write(message);
...
byte[] buffer = new byte[4];
running = true;
ret = mInputStream.read(buffer);
www.udoo.org

36. Programming Arduino
To program SAM3X we need to download Arduino IDE based on
Processing project.
Arduino programming language is based on C / C++ with specific
objects that provides main arduino’s functions.
It provides an interface with the microcontroller low level C
programming language.
It allows to avoid “unfriendly” low level difficulties (write or read
registers, manage signals timings, non objects).
www.udoo.org

37. Programming Arduino
Arduino sketches have a defined structure based on two main
functions:
- void setup()
- void loop()
Setup method is executed at the beginning of the sketch, and it’s
used to initialize objects.
Loop method is executed continuously after first setup execution. It
contains the core of the code.
www.udoo.org

38. Programming Arduino
Example for blinkin LED:
int led = 13;
void setup() {
pinMode(led, OUTPUT);
}
void loop() {
digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000);
// wait for a second
digitalWrite(led, LOW); // turn the LED off by making the voltage LOW
delay(1000);
// wait for a second
}
www.udoo.org

39. Arduino .ino
The accessory code must make a few calls to initialize USB
connectivity, including setting the accessory identification strings:
char descriptionName[] = "UDOOAndroidADKDemo";
char modelName[] = "UDOO_ADK";
char manufacturerName[] = "Aidilab";
char versionNumber[] = "1.0";
char serialNumber[] = "1";
char url[] = "http://www.udoo.org";
USBHost Usb;
ADK adk(&Usb, manufacturerName, modelName, descriptionName, versionNumber, url,
serialNumber);
www.udoo.org

40. Arduino .ino
read data from Android App into buffer:
void loop(){
uint8_t bufRead[BUFSIZE];
uint32_t nbread = 0;
uint8_t bufWrite[1];
if (adk.isReady()) {
adk.read(&nbread, BUFSIZE, buf); // read data into buf array
if (nbread > 0) {
... // do stuff
www.udoo.org

41. Arduino .ino
write data to Android App:
void loop(){
uint8_t bufWrite[BUFSIZE];
...
...
adk.write(sizeof(bufWrite), (uint8_t *)bufWrite);
www.udoo.org

42. Android ADK useful links
● Android ADK Documentation
http://developer.android.
com/guide/topics/connectivity/usb/accessory.html
http://developer.android.com/tools/adk/adk2.html
● Toolkit to help beginners to be up and running with ADK 2012:
https://github.com/palazzem/adk-toolkit
by Emanuele Palazzetti (GDG Perugia)
www.udoo.org

43. Arduino Resources & Community
Downloads:
http://arduino.cc/en/Main/Software
http://www.udoo.org/downloads/
Resources:
http://arduino.cc/en/Tutorial/HomePage
http://arduino.cc/en/Reference/HomePage
Community:
http://forum.arduino.cc/
more… more.. and more
www.udoo.org

44. Projects
www.udoo.org

45. Community: www.udoo.org
• Informative
website
• Forum
• Tutorials
• Projects
• Wiki
• Support
• Faq
www.udoo.org