Transcript RFID Smart Home System - School of Electrical and Computer

David Meyers, Jared Santinelli, Phillip Robinson,
Nazar Trilisky
Georgia Institute of Technology
School of Electrical and Computer Engineering
October 23, 2008

Goal: Prototype of an RFID-based access control
system featuring adaptive lighting

Target Customer: Builders and developers of Multiple
Dwelling Units (MDUs)

Motivation: Increase security and convenience while
saving money

Target Cost: Prototype < $500

Provide automated entry/exit and identification using RFID

Supply the ability to track occupants within a database

Automate hallway lighting dependent upon user
destination

Turn on foyer light based on current natural lighting
conditions

Use electric door strikes to lock doors for security

Basic Layout
 Red- “Entrance/Exit Module”
 Green – “Room Module”
Phidget RFID Reader (USB)
 Board Dimensions: 6.8 x 8.1 cm
 EM4102 Passive Tags @ 125 kHz
(Read Only)
 Read Range (depends on tag type)
▪ Vertical: 0.5 in to 4 in
▪ Lateral: 0.5 in to 2 in
 Min Distance Between Readers: 1 m
 Available +5 VDC and LED Output


eBoxII
Available Interfaces
 3 USB ports – For RFID Reader Communication
 1 RS-232 port – For Microcontroller Communication
 1 Ethernet
 1 Monitor Connection
 PS/2 Mouse/Keyboard Connection

OS/Application languages
 Windows CE 6.0
 C/C#/C++/Java

CY8C29466-24PXI
 19 Digital General Purpose I/O Pins
 Maximum 80 mA combined IOH budget
 VOH = Vdd – 1 V = 4 V Min.
 VOL = .75 V Max.

Interfaces
 eBox: RS-232 TxD Pin #3  Rx8 Serial Reader
 Circuit: I/O Pins wired to transistors

Door Strike (SD-995C)
 Triggered with 7.3 V differential
 Fail-safe or Fail-secure modes

Relays
 Operate at 80-100% of specification voltage
 DP-DT increases scalability

Photovoltaic Switch
kc7786 - Passive Infrared Sensor (PIR) module
Lens angle: 60° vertical, 100° horizontal
Created
from +12
VDC using
555 timer
C1 and R3 determine
timing characteristic
Problems
Solutions
Motion detector has very small
output voltage
Used operational amplifier to
increase signal level
Need to create -12 VDC supply
from +12 VDC
Used 555 timer
LCD display on EVAL board not
working
Using LEDs for debug
Receiving RS-232 input on
Microcontroller
In Progress: adjusting timer,
voltages, and parameters of
Rx8 module
Errors when building OS solutions In Progress: working with lab
for eBoxII
TAs to troubleshoot
Room Door
Unlocks
Light On
1
Test 1: Invalid Tag
Test 2: Valid Tag
Room 1
Test 3: Valid Tag
Room 2
Room Door
Hallway
Lights On
Lights On
2
Main
Door
Main Door
Main Door
Remains
Unlocked
Locks
Locked

Cost Analysis:
 Prototype Cost – Approx. $451.97
 Target Price for 50-unit building - $38,600.00
 Based on 490 units sold, 5 year profit - $1,090,119.00

Current Market:
 Non-Integrated Devices - ~11% cheaper, less flexible
 Best Buy ConnectedLife.Home - $15,000 for typical 3-
bedroom family residence

Complete
 Design and Theory
 Initial Component Testing
 Motion Detector/Timer Circuit

In Progress
 eBox Software Testing (11/12/08)
 Circuit/Simulation Environment Construction (11/12/08)
 Microcontroller Software Testing (11/12/08)

Planned
 System Integration and Testing (11/12/08 – 11/28/08)
 Ready for Demo and Presentation (11/28/08)