introduction to crossbow mica2 sensors

8/2/2019 Introduction to Crossbow Mica2 Sensors

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Introduction to Crossbow Mica2 SensorsPrasanna Ballal

Automat ion & Robotics Research I nstit ut eUniversity of Texas at Arlington

EE5369 Sensor Netw orksDr. Frank Lew is


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What is mica2 ?Mica2:

-processing,

-storage

-power supply

-sending data to base station

Sensing board:-sensing (temperature, light,

accelerometer & magnetometer)


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Why mica2? mica2wireless platform serves as a

foundation for various WSN

applications. Hundreds of research groups all over

the world (including UTA) use mica2nodes

mica2is created with off-the-shelf

hardware mica2does not require use of

predefined protocols (except mica Z)


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System architecture Logical architecture

RFCommunication

I/OSub-system

Storage

Power management

Processing


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System architecture


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System Architecture Constraints

4KB RAM

128KB Program Flash Memory

> 25mA (Tx) , < 15uA (sleep) at 3.3V 8MHz Microcont roller

19.2Kbps (at 433 or 916MHz)

Other excit ing details

512KB Measurement Flash 4KB Conf igurat ion EEPROM

10bit ADC

3 LEDs

51pin expansion connector

Transmission range ~ 500f t outdoor

Runs on 2 AA bat teries


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Processing sub-system Functions

Application execution

Resource management Peripherial interaction


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Processing sub-systemFunctions

Application Execution

Resource ManagementPeripheral I nt eract ion

Atmel AVR ATMEGA128L

RI SC Archi t ecture

8 bit ALU/ data-path128 Kb FLASH - Code

4 Kb SRAM - Data

Mult iple peripherals

Details are available in the ATMEGA128L Datasheet


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Logical architecture

RFCommunication

I/OSub-system

Storage

Power management

Processing


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I/O Sub-System Functions

Interface with sensing boards

Interface with programming boards Program and communicate with other

devices


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RFCommunication

I/OSub-system

Storage

Power management

Processing


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Secondary storage Sub-System Functions

stores sensor data logs

temporarily holds program images receivedover the network interface


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RFCommunication

I/OSub-system

Storage

Power management

Processing


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Power management Sub-System Functions

regulate the systems supply voltage


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RFCommunication

I/OSub-system

Storage

Power management

Processing


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RF Communication Sub-System Functions

Transmit Receive data packets

wirelessly Co-ordinate/ Netw ork w ith other

nodes

Implementat ion

Radio Modulat ion Demodulat ion Two types of radios: RFM, ChipCon

CC1000 RFM: Mica & pr edecessors

CC1000: Mica2 onw ards AVR

Protocol Processing


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Sensing Sub-System Functions

Sampling physical signals/phenomena

Different types of sensors Photo-sensor

Acoustic Microphone

Magnetometer Accelerometer

Sensor Processor Interface

51 Pin Connector

ON-OFF switches for individual sensors

Multiple data channels


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Other sensor boardsUltrasonic transceiver

LocalizationUsed for rangingUp to 2.5m range6cm accuracy

Dedicated microprocessor25kHz element

Basic Sensor boardLight (Photo), Temperature,

Acceleration, Magnetometer,

Microphone, Tone Detector,

Sound


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References

www.xbow.com

www.tinyos.net

Datasheets: Atmel 128l, Atmel 103l,Maxim 1678, RM 4041, DS1804,TR1000, CC1000, CC2420

introduction to crossbow mica2 sensors

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