1. Example Distributed Sensor Network with TinyOS Motes RPI ECSE – 6965/4694 Daniel Casner 2007 April 13th

2. Daniel Casner2 Outline Hardware Applications Implementation (software)

3. 2007 April 13thDaniel Casner3 Hardware

4. 2007 April 13thDaniel Casner4 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

5. 2007 April 13thDaniel Casner5 Applications Temperature Estimation –Measure local temperature –Repeatedly average with neighbors –Converges to global average Event Notification –Detect an event –Notify whole network

6. 2007 April 13thDaniel Casner6 Initializing the Network Store neighbor information Power On Wait to hear from neighbors Is new? No Yes Broadcast existence Hear from neighbor Periodically rebroadcast our existence

7. 2007 April 13thDaniel Casner7 Source Code

8. 2007 April 13thDaniel Casner8 Distributed averaging algorithm 1.Take a number 2.Pick a random person 3.Average your two numbers 4.Both of you store the new number It should be between 1 and 100 5.Go to step 2 and repeat 6.When you see the same number several times in a row, sit down.

9. 2007 April 13thDaniel Casner9 Even node j On the Motes Odd node i Send current estimate to random odd neighbor Update local estimate Measure local temperature Receive message Message type Returned estimate NACK Receive message Average with local estimate Send NACK Send update Is busy? NoYes

10. 2007 April 13thDaniel Casner10 Deadlock 1 4 2 3 Now what?

11. 2007 April 13thDaniel Casner11 With Even/Odd Roles 1 4 2 3

12. 2007 April 13thDaniel Casner12 Source Code

13. 2007 April 13thDaniel Casner13 Multi-hop event routing At each node: Node i Network initialization (identify all neighbors) Initialize sensors Send event notification to all neighbors k ≠ j ≠ i Node j Detect event Receive event notification from neighbor

14. 2007 April 13thDaniel Casner14 Source Code

15. 2007 April 13thDaniel Casner15 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

16. 2007 April 13thDaniel Casner16

17. 2007 April 13thDaniel Casner17 Mica2 Specifications

18. 2007 April 13thDaniel Casner18 Demonstrations Off / Initializing Neighbor discovery Switching modes Temp estimation Photo event detection Event detected