Slides of presentation given at Sun Tech Days 2007 in Milan about Sun SPOTs programming.

1. Introducing
the Sun SPOTs
Stefano Sanna
Senior Developer
JUG Sardegna ONLUS
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2. About Me
• Senior developer @ beeweeb technologies
• Technical writer @ DEV, Computer Programming,
Java Journal...
• Supporter @ JUG Sardegna, JMDF, JIA, GULCh
• LEGO constructor since 1973...
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3. Java User Groups in Italy
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4. Program the (Real) World
• Wireless sensor networks open new exciting
scenarios:
> pervasive monitoring of environment and structures
> massive distributed intelligence
> urban smart objects
• Programmable Objects for Real World
> connected: the Internet of Things
> autonomous: local CPU, local memory, local code
> environment-aware: sensors
> safe and robust
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5. Sensors: New Frontier of Interaction
• To be programmable and connected is not enough!
• The ability to “perceive” the surroundings is the next
interaction frontier for consumer and mobile devices
• Gaming console, mobile phones, automotive
appliances, embedded systems: any object is
expected to “sense” and act according to physical
quantity such as temperature, light, acceleration,
position, humidity, proximity...
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6. Sensors in the Java ME World
• Java ME is leading technology for mobile
applications, ranging from cellular phones to
embedded systems
• A rich set of standard API enables multimedia
capabilities, 2D and 3G graphics, local and remote
connectivity, location, NFC...
• The Java Community Process has published the
Mobile Sensor API (JSR 256) for accessing devices
such as accelerometers, thermometers, light sensor
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7. Introducing the Project Sun SPOTs
Small Programmable Object Technology
• Project from Sun Laboratories
• Platform for intelligent wireless
sensors network
• Live-laboratory for implementing
new computing scenarios:
> The (Inter)net of Things
> Program the world
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8. Sun SPOT Presentations
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9. SPOTs Hardware
• Processor Board
> 180 MHz 32 bit ARM920T core
512K RAM/4M Flash
> 2.4 GHz IEEE 802.15.4 radio
with integrated antenna
> USB interface
> 3.7V rechargeable 720 mAh
lithium-ion battery
> 32 uA deep sleep mode
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10. SPOTs Hardware
• Demo Sensor Board
> 2G/6G 3-axis accelerometer
> Temperature sensor
> Light sensor
> 8 tri-color LEDs
> 6 analog inputs, 2 switches
> 5 general purpose I/O pins
> 4 high current output pins
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11. SPOTs Software
• Squawk Virtual Machine
> Fully capable J2ME CLDC 1.1
Java VM with OS functionality
> VM executes directly
out of flash memory
> Device drivers written in Java
> Automatic battery management
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12. Sun SPOT Java Development Kit
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13. Free-Range and Basestation
• Sun SPOT Development Kit provides:
> Two free-range SPOTs, equipped with Processor Board,
radio interface, Demo Sensor and battery
> One basestation SPOT, with Processor Board and radio
interface
> SDK for Windows, Mac OS X, Linux
> USB cable
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14. Development
• SDK comprises libraries and utilities for compiling
and packaging bytecode, updating SPOTs firmware,
running basestation applications
• SDK is based on Ant tasks and can be integrated in
any IDE, e.g. Netbeans
• SPOTs support remote installation, execution and
debugging of applications through wireless
connection
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15. Applications
• Sun SPOT Applications
> Run on free-range SPOTs
> CLDC 1.1 and IMP 1.0 application model
> Full access to peripherals and demo board
• Sun SPOT Host Applications
> Run on a SPOT configured as basestation
> Stand-alone application model
> Simultaneous access to SPOT and JSE libraries
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16. Classes, Devices, Sensors, Interfaces
• There are over 400 classes documented in the Sun
SPOT javadoc: nearly three times the MIDP 2.0
specification! :-)
• The Sun SPOT device library contains drivers and
high-level classes to access physical interfaces and
peripherals:
> ILed
> IlightSensor, IAccelerometer3D
> IFlashMemoryDevice
> IPowerController
> IPWMOutput
> IAT91_PIO, IAT91_IAC...
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17. Radio Communication
• Sun SPOTs come with low-range IEEE 802.15.4
radio module
• Communication API is based on Generic
Connection Framework and provides:
> RadioConnection (radio://) from stream-based
communication
> RadiogramConnection
(radiogram://) for datagram
based communication
> basestation may act as
proxy for HTTP connections
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18. Sun SPOTs Projects
• Many projects based on Sun SPOTs have been
published on the Web: just use your preferred
search engine or video repository to find them!
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19. Mashing-up Hardware and Software
• The Sun SPOTs let developers build their custom
interfaces for virtually any kind of electronic
peripheral:
> sensors
> motors
> microcontrollers
> radio equipment
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20. Be Careful with Solder... :-(
• However, soldering and designing circuits and
interfaces for physical components require some
specific expertise
• Wrong assembly or accidental short circuit may
definitively damage your SPOTs and/or your
peripherals
• How can we exploit Sun SPOTs potential without
setting-up a electronic lab?
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21. Fun for Everyone! :-)
• Thanks to the basestation, we can use the PC as
gateway to any resource such as USB devices,
network hosts and Bluetooth peripherals
• LEGO Mindstorms NXT kit provides:
> Easy and flexible
> 3 outputs
> 4 inputs
> Bluetooth and USB interfaces
> Open source iCommand Java library provides easy and
powerful API for remote NXT control
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22. “Real” Gesture Controller for Vehicle
USB
802.15.4
radio
Bluetooth
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23. Overview
• The Gesture Controller
> Runs on a free-range SPOT
> Reads tilt degrees on X and Y axes
> Sends message to Vehicle Controller
• The Vehicle Controller
> Runs on the basestation
> Receives messages from Gesture Controller
> Sends commands to NXT Vehicle
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24. The Gesture Controller (source.1)
public class SunSpotApplication extends MIDlet {
private IAccelerometer3D accelerometer =
EDemoBoard.getInstance().getAccelerometer();
private ISwitch switch1;
private int st=0;
private RadiogramConnection conn;
protected void startApp() throws
MIDletStateChangeException{
switch1 =
EDemoBoard.getInstance().getSwitches()[0];
runSwitchWatcher();
}
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25. The Gesture Controller (source.2)
protected void pauseApp() {
// This will never be called by the Squawk VM
}
protected void destroyApp(boolean arg0)
throws MIDletStateChangeException {
}
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26. The Gesture Controller (source.3)
private void runSwitchWatcher(){
Thread t1 = new Thread(){
public void run(){
sw1.waitForChange();
if (conn == null) {
try {
conn = (RadiogramConnection)
Connector.open(quot;radiogram://broadcast:133quot;);
startAccelerometerWatcher();
} catch (Exception e) { }
}
}
};
t1.start();
}
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27. The Gesture Controller (source.4)
public void startAcceWatchThreadd(){
Thread t2 = new Thread() {
public void run() {
while(true){
readTildAndSend();
}
}
};
t2.start();
}
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28. The Gesture Controller (source.5)
private void readTiltAndSend() {
try {
int tiltX = (int) Math.toDegrees(acc.getTiltX());
int tiltY = (int) Math.toDegrees(acc.getTiltY());
String data = Integer.toString(tiltX) +
quot;#quot; + Integer.toString(tiltY);
send(data);
} catch (IOException ex) { }
try {
Thread.sleep(100);
} catch (InterruptedException ex) { }
}
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29. The Gesture Controller (source.6)
private synchronized void send(String data) {
if (conn != null) {
try{
Datagram datagram =
conn.newDatagram(conn.getMaximumLength());
datagram.writeUTF(data);
conn.send(datagram);
} catch(IOException e){ }
}
}
}
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30. The Vehicle Controller (source.1)
public class SunSpotHostApplication {
private static final int FORWARD = 0;
private static final int BACKWARD = 1;
private static final int RIGHT = 2;
private static final int LEFT = 3;
private static final int STOP = 4;
private int last = STOP;
private static Pilot pilot; // iCommand Java NXT Library
public static void main(String[] args) {
SunSpotHostApplication app = new
SunSpotHostApplication();
startNXT();
app.start();
}
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31. The Vehicle Controller (source.2)
private static void startNXT() {
try {
NXTCommand.open();
pilot = new Pilot(2.1f,4.4f,Motor.A, Motor.C,true);
} catch(Exception e) {
e.printStackTrace();
}
}
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32. The Vehicle Controller (source.3)
public void run() {
try{
RadiogramConnection conn =
(RadiogramConnection) Connector.open(quot;radiogram://:133quot;);
Datagram datagram =
conn.newDatagram(conn.getMaximumLength());
while(true){
datagram.reset();
conn.receive(datagram);
String rawData = datagram.readUTF();
String[] tokens = rawData.split(quot;#quot;);
moveVehicle(tokens[0], tokens[1]);
}
}catch(IOException e){ e.printStackTrace(); }
}
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33. The Vehicle Controller (source.4)
private void moveVehicle(String accelX, String accelY) {
int tiltX = (int) Double.parseDouble(accelX);
int tiltY = (int) Double.parseDouble(accelY);
if (tiltY > 15) {
if (last != BACKWARD) {
pilot.backward();
last = BACKWARD;
}
} else if (tiltY < -15) {
if (last != FORWARD) {
pilot.forward();
last = FORWARD;
}
}
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34. The Vehicle Controller (source.5)
else if (tiltX < -25) {
if (last != RIGHT) {
pilot.rotate(30);
last = RIGHT;
}
} else if (tiltX > 25) {
if (last != LEFT) {
pilot.rotate(-30);
last = LEFT;
}
} else {
if (last != STOP) {
pilot.stop();
last = STOP;
}
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35. DEMO
(Murphy Law loading... please wait...)
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36. Conclusions
• Sensors are the new frontier of interaction
• The Sun SPOTs are the quot;cool Java wayquot; to create a
quot;live labquot; for innovative scenarios
of ubiquitous and
pervasive computing
• Extended class library
and full integration of
basestation with
desktop PC gives
everybody the opportunity to HAVE FUN with SPOT
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37. References
• Sun SPOT World
> http://www.sunspotworld.com
• Sun SPOTs and Java robotics on java.net
> https://sunspot-robotics.dev.java.net/
> http://community.java.net/robotics/
• Sun SPOT purchasing:
> http://www.sunspotworld.com/products
> http://store.systronix.com
• LEGO Mindstorms NXT
> http://mindstorms.lego.com
> http://lejos.sourceforge.net 37

38. Contacts
• Stefano Sanna
> gerdavax@tiscali.it – http://www.gerdavax.it
• JUG Sardegna ONLUS
> http://www.jugsardegna.org
• Java Mobile Developers Forum
> http://www.jmdf.org
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39. Introducing
the Sun SPOTs
Stefano Sanna
Senior Developer
JUG Sardegna ONLUS
39