This document introduces Sun SPOT (Small Programmable Object Technology), a wireless sensor network platform from Sun Microsystems for creating intelligent sensor networks and interacting with the physical world. It describes the Sun SPOT hardware which includes a processor board and sensor board, and the Sun SPOT software which uses the Squawk virtual machine to run Java ME applications. It provides examples of using the Sun SPOT to build a gesture controlled vehicle by having one SPOT read gesture sensor data and send messages over radio to another SPOT acting as a base station which controls a LEGO Mindstorms vehicle.

1. Introducing
the Sun SPOTs
Stefano Sanna
Senior Developer
JUG Sardegna ONLUS
1

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