Sun SPOT

Introduction

Miloš Solujić

OutlineSPOT – beginnings Technical details - hardwareTechnical details - softwareBasestationsSPOT – Pros and ConsExample applicationQuestions

SPOT – beginnings SPOT stands for Small

Programmable Object Technology

Java is already available on few bilion cellphones – next step is SPOT

Sun Labs launched new platform for playing with sensing on Java ME

It is Java ME – CLDC – MIDP compatible

Technical details - hardware

180 MHz 32 bit ARM920T

512K RAM - 4M Flash2.4 GHz IEEE 802.15.4

radioUSB interfaceExample Board:2G/6G 3-axis

accelerometerTemperature sensor Light sensor

Technical details - hardware

8 tri-color LEDs6 analog inputs2 momentary switches5 general purpose I/O

pins4 high current output

pinsBattery can operate for

few weeks if application is well designed

Technical details - software Squawk – Java virtual machine

written in Java, for SPOT, but not only

Designed for resource constrained systems, like SPOT

Manages power and other features of SPOT transparently for programmer

Isolates – support for multiple independent execution spaces

Aim is to be fittable on 16KB in future

Technical details - software Lots of libraries, with drivers for:

◦The on-board LED◦The PIO, AIC, USART ◦The CC2420 radio chip, IEEE

802.15.4◦The base-station support◦The over-the-air (OTA)◦The radio policy manager◦And so on…

Technical details - software – example code using libraries

String ourAddress = System.getProperty("IEEE_ADDRESS"); IScalarInput lightSensor =

EDemoBoard.getInstance().getLightSensor(); ITriColorLED[] leds =

EDemoBoard.getInstance().getLEDs(); System.out.println("Starting sensor sampler

application on " + ourAddress + " ..."); System.err.println("Caught " + e + " in connection

initialization."); now = System.currentTimeMillis(); // Go to sleep to conserve battery

Utils.sleep(SAMPLE_PERIOD - (System.currentTimeMillis() - now));

Technical details - software

SPOT applications conform to the MIDlet standard

startApp(), pauseApp() and destroyApp()- three methods to be implemented in any on-SPOT application

Basestations

Basestations:• to allow applications running on the Host to interact

with applications running on Targets• may run in either dedicated or shared mode• any Sun SPOT can be used as the basestation• ant startbasestation is needed to start

SPOT attached via USB as basestation

SPOT – pros and consPros

◦Java enabled◦It is low steep curve of learning for

SPOT◦Good documentation, community◦Simulator

Cons◦Not so small◦Security not on high level◦Some issues working with linux

Example application:Symbiotic NetworksConcept introduced by David

Loftus and Srdjan Krco, Ericsson Ireland

Current status: prototype of system is designed and implemented

It is tested in laboratory conditions

Symbiotic NetworksSystem overview

• Highly decomposable system design, still possible to deploy on single PC

• Proof of concept level of implementation, but good base for design of enterprise-level application

Data Collection Point - DCP

DCP – Some State Diagram

EVENT REPORTING

Presented main part of work method in DcpReporter

No unnecessary processor working

Good scalability = dozens of sensors on same base station with humble resources

Control Centre - CC

Symbiotic Networks - Screenshots

Symbiotic Networks - Screenshots

Symbiotic Networks - Screenshots

Questions…

Contact:Miloš Solujić, sole@etf.rs