intro-sunspot.pdf

Sistemas Embebidos 2013/14

Intro to SunSPOTs 1

Introduction to

SunSPOTsSistemas Embebidos 2013/14

Pedro Brandão

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References

Based on slides from Luís Lopes and Pedro Lopes

Nik Shaylor, Douglas N. Simon William R. Bus, “A

Java Virtual Machine Architecture for Very Small

Devices”, Language, Compiler, and Tool Support

for Embedded Systems: Proceedings of LCTES ’03,

number 38(7), 2003

See also SunSPOT’s programmers’ Guide

SE 2013/14 - Intro SunSPOTs - pbrandao

2

http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.67.9899


Intro to SunSPOTs 2

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This is a SunSPOT


3

(OK 2 SunSPOTs )

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Board


4

Antenna

Processor

ARM920T

180MHz 32 bits

Switch

Radio 802.15.4

IEEE 2.4 GHz

512 KB RAM

4 MB Flash

USB Interface


Intro to SunSPOTs 3

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Sensor Board


5

8 LEDs

3 colours

Light sensor

digital and

analogue pins

Switchs

3 axis

accelerometer

Temperature

sensor

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Energy source

Lithium batteries, 3.7V/750 mAh, rechargeable

Deep sleep mode of 30 µA

What components are running affects deep sleep possibilities

Automatic power management by software

See the programmer’s guide on “Powering a

Spot” and “Conserving power”


6


Intro to SunSPOTs 4

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Squawk Virtual Machine

Architecture split-vm

Implemented in Java

No Operating system

Compacter Byte-

code

Simpler Garbage

collection


7

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Split-VM architecture

Classes loaded at host

Format (.suite)

compacter than .classor .jar

.suite files have no

compression


8


Intro to SunSPOTs 5

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Simplified Bytecode

Compacter (35% - 45% of equivalent J2ME code)

No dynamic loading

Immutable

Simplified memory management


9

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.suite files

A .suite file is a collection of classes

Each class in a .suite file only refers to classes within the file or in the father .suite.


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Intro to SunSPOTs 6

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.suite files (cont)

When a .suite is closed no more classes can be

added

It becomes immutable

It can be kept in a single file and loaded from it.

A static and efficient process

Each SPOT can have several .suite in execution,

distributed in independent address spaces,

named isolates


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SunSPOT SDK

SunSPOTs applications are MIDLETs

They extend the javax.microedition.midlet.MIDlet class

Applications implement:

startApp, pauseApp e destroyApp

See the /Demos/CodeSamples/SunSpotApplicationTemplate

Communications use wireless channel with:

radiogram and radiostream


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Intro to SunSPOTs 7

On to the demo…


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intro-sunspot.pdf

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