Example Distributed Sensor Network with TinyOS Motes

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Example Distributed Sensor Network with TinyOS
Motes

• RPI ECSE 6965/4694
• Daniel Casner
• 2007 April 13th

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Outline

• Hardware
• Applications
• Implementation (software)

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Hardware
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Hardware

• Processing
• ATmega128L
• 7MHz
• 64Kb RAM
• Radio
• 900 MHz
• 38.4 Kbps
• Storage
• Program 128Kb flash
• Data 512Kb flash

• Sensors (10 bit ADC)
• Magnetometer (x,y)
• Microphone
• Photo
• Seismic
• Temperature
• Actuators
• Piezoelectric buzzer

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Applications

• Temperature Estimation
• Measure local temperature
• Repeatedly average with neighbors
• Converges to global average
• Event Notification
• Detect an event
• Notify whole network

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Initializing the Network
No
Broadcast existence
Is new?
Wait to hear from neighbors
Power On
Hear from neighbor
Yes
Periodically rebroadcast our existence
Store neighbor information
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Source Code
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Distributed averaging algorithm

• Take a number
• Pick a random person
• Average your two numbers
• Both of you store the new number
• It should be between 1 and 100
• Go to step 2 and repeat
• When you see the same number several times in a
  row, sit down.

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On the Motes
Measure local temperature
Measure local temperature
Receive message
Send current estimate to random odd neighbor
Is busy?
Receive message
No
Yes
Message type
Average with local estimate
Send NACK
Returned estimate
NACK
Update local estimate
Send update
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Deadlock
1
4
2
3
Now what?
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With Even/Odd Roles
1
4
2
3
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Source Code
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Multi-hop event routing
At each node
Network initialization (identify all neighbors)
Node j
Initialize sensors
Detect event
Receive event notification from neighbor
Send event notification to all neighbors k ? j ? i
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Source Code
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References

• Source code on LMS
• TinyOS www.tinyos.net
• Download
• Tutorials
• Examples
• Crossbow www.xbow.com
• Mica2 Motes
• UC Berkeley webs.cs.berkeley.edu
• Original TinyOS and Mote development

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(No Transcript)
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Mica2 Specifications
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Demonstrations