Guided By:Prof. Sachin Gajjar

IRIS Wireless Sensor Mote

What is Wireless Sensor Network??

• A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations.

• The WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors.

Applications Of WSNi. Military applications such as battlefield

surveillance.

ii. Traffic Control

iii. Area Monitoring

iv. Industrial Monitoring

v. Landslide detection

vi. Air pollution monitoring

vii. Structural monitoring

viii. Greenhouse monitoring

ix. Agriculture

Requirements for Wireless Sensor Networks

› Efficient utilization of energy and power

› Small Footprint

› Should support diversity in design and usage

› More emphasis on Concurrent execution

› Interleaving flows, events, energy management

› Allow appropriate abstractions to emerge

Sensor Node A sensor node, also known as a mote is a node in

a WSN that is capable of performing some processing, gathering sensory information and communicating with other connected nodes in the network.

WHAT IS IRIS?? The IRIS is a 2.4 GHz Mote used for enabling low-power wireless sensor

networks.

Available as a module (M2110) or board-level platform (XM2110), IRIS provides users with high-level functional integration designed to optimize the addition of wireless mesh networking technology to a wide variety of custom sensing applications providing up to three times improved radio range and twice the program memory over previous generations of MICA Motes.

Features of IRIS MoteI. Outdoor line-of-sight tests have yielded ranges as far as

500 meters between nodes without amplification.

II. 250 kbps data rate

III. Resistant to RF interference and provides inherent data security.

IV. 2.4 to 2.48 GHz, a globally compatible ISM band

V. Ultra low-power consumption with half the sleep current of previous motes for longer battery life

MI B520 –USB INTERFACE BOARD Base Station for Wireless Sensor Networks

Any IRIS node can function as a base station when mated to the MIB520CB USB interface board

In addition to data transfer, the it also provides a USB programming interface.

51pin connector & Baud Rate: 57.6 K

Processor & Radio Platform (MPR2400CA)

The MPR2400 is based on the Atmel ATmega128L , a low-power µcontroller

The 51-pin expansion connector supports Analog Inputs, Digital I/O & UART interfaces.

PROGRAMMING WSN MOTES

A separate operating system is used for programming motes of WSN : TinyOS

Introduction to TinyOS TinyOS began as a collaboration between University

of California, Berkeley and Intel Research.

It is a free open source operating system designed for wireless sensor networks.

It is an embedded operating system written in NesC,a dialect of C language.

It features a component based architecture.

TinyOS has several features: A simple event-based concurrency model, and split-phase operations.

Why ‘ TinyOS’ ??

Problems with traditional OSi. Multithreaded Architecture not useful

ii. Large Memory Footprint

iii. Does not help to conserve energy and power

iv. Command processing loop (wait request, act, respond)

Features Of TinyOSi. Component based architecture which allows

frequent changes while still keeping the size of code minimum.

ii. It is power efficient as it makes the sensors sleep as soon as possible.

iii. Event based execution model means no user boundary and hence supports high concurrency.

Hence TinyOS

About nesConesC (network embedded system C) is a language

used to build applications in TinyOS.

o It is designed in such a way to exhibit the concepts

and execution model of TinyOS.

TOSSIM TOSSIM is a discrete event simulator for TinyOS

sensor networks.

Instead of compiling a TinyOS application for a mote, users can compile it into the TOSSIM framework, which runs on a PC.

This allows users to debug , test and analyze algorithms in a controlled and repeatable environment.

As TOSSIM runs on a PC, users can examine their TinyOS code using debuggers and other development tools such as TinyViz.

Imperfections Of TOSSIMAlthough TOSSIM captures TinyOS behaviour at a

very low level, it makes several simplifying assumptions, e.g. Battery life, non-preemptive interrupt.

While TOSSIM can be used to understand the causes of behaviour observed in the real world, it does not capture all of them , and should not be used for absolute evaluations.

This means that it is very possible that code which runs in a simulation might not run on a real mote.

References http://www.tinyos.net

http://en.wikipedia.org

http://www.memsic.com/products/wireless-sensor-networks/wireless-modules.html