Matt Gilliland , Andrew Gonzalez, Youngki Hong, and Nadia Lutful

1
WIRELESS SENTINEL
Matt Gilliland , Andrew Gonzalez, Youngki Hong,
and Nadia Lutful
mrg046000_at_utdallas.edu, axg038200_at_utdallas.edu,
ykh063000_at_utdallas.edu, nxl062000_at_utdallas.edu
Department of Electrical Engineering Erik Jonsson
School of Engineering Computer
Science University of Texas at Dallas Richardson,
Texas 75083-0688, U.S.A.
Goals

• Sensor Detection Circuit layout is given below
• High pressure on the sensor
• Two voltage dividers
• TI Linear Regulator and OP Amp (LMV 772)

• TI Regulator schematic is given below

• To design and implement a system for a vest that
  will detect the impact of a force and send a
  distress signal and location to the police base

• OP Amp (LMV722) schematic is given below

• The flowchart for the microcontroller
  programming is given below
• Microcontroller compares output voltage from
  sensor with threshold voltage and get data from
  GPS
• If greater than threshold, send signal to
  Transmitter or keep waiting

Overview

• The design was divided into the followings
  units
• Power supply unit
• Pressure detection unit
• Logic unit
• Wireless unit

• After a certain amount of force is applied,
  output voltage peaks to 3V

• Debugging the end device and displaying Google
  Maps

• The final system works as follows
• Piezo-resistive sensors detects the applied
  force
• Vest circuitry includes a GPS to log current
  location
• A TI MSP430 microcontroller detects voltage
  change by the sensor upon impact and activates
  transmitter
• RF Transmitter sends distress signal along
  with GPS data to police base
• RF Receiver on the laptop receives transmitted
  signals
• GPS data converted to Google Maps to pin point
  location

• Motherboard where all circuits are connected and
  individual detection circuit

Project Timeline

• Designed and implemented voltage detection
  circuit for sensors
• Programmed microcontroller for voltage detection
  circuits
• Programmed microcontroller for GPS
• Transmitted data to receiver
• Converted GPS data to Google Maps by using python
  code
• Completed system integration

Outcomes