P1254413710vaghH

1
http//www.ece.cmu.edu/ece549/spring07/team8/
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Priya Narasimhan Junwei Chuah Shihong Ng Mingyang
Koh
C A N T T O U C H T H I S
Architecture
Motivation

• Motion Detection
• Accelerometer communicates motion to Tmote
• Dual activation/deactivation of state
• Armed by user/ sensing distance between user and
  device
• Disarmed by password / sensing distance between
  user and device
• Serial communication b/w laptop and device
• TOSMsg packet sent from device to laptop
• Individual bytes sent from laptop to device
• Zigbee Protocol
• Used hysteresis to buffer the change in
  arm/disarm states

• A laptop owner today is unable to leave his/her
  laptop unattended for a short period of time
  without risk of the laptop being stolen.
• With our system, an alarm will sound if the
  laptop is being handled by unauthorized personnel.

• Objective
• Develop a cost effective anti-theft device for
  every laptop user.
• Eventually embedded inside every laptop.

Development Environment

• Hardware
• Moteiv Tmote Sky
• Spark Fun Electronics Triple Axis Accelerometer
  Breakout ADXL330
• Software
• Java
• TinyOS

Results

• Almost every sudden movement would cause alarm to
  ring
• Thief can steal laptop by moving it away slowly
• Banging of lab table does not cause alarm to
  sound off most of the times
• Device will be in disarm mode constantly if user
  within 1.5 feet
• Device will likely be in arm mode constantly if
  user is at 16 feet from device

• Protocols
• USB
• Zigbee