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SafeGuard: Anti-Theft/Reminder Transmitter Group: #3 Carson Hammoser Peter Lin Albert Uang Samuel Wong. The Problem. Lost and Forgotten Items Lost Property Office of Transport for London 130 000 items between April 2003 and March 2004
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SafeGuard: Anti-Theft/Reminder Transmitter Group: #3 Carson Hammoser Peter Lin Albert Uang Samuel Wong
The Problem • Lost and Forgotten Items • Lost Property Office of Transport for London 130 000 items between April 2003 and March 2004 • 11300 Laptops, 31400 PDA’s, 200 000 Cell phones Left in the backs of cabs • Security • 5035 Pickpocket crimes in London Underground • Keeping Track of Kids and Pets • 58200 Child Abductions in US
Solution • A tracking device that warns the user when things are left behind or move too far away • Able to track multiple items • Able to recognize each item
Proposed Product: The SafeGuard • Wireless electronic tether • Tracks multiple objects on one transmitter • Audio warning when items are out of range • Programmable Identification of Item
System Overview: • User places RF tags on selected items • Clip to your Cell phone/PDA • Slip into your wallet / jacket pocket • Place In glasses Case • Place in backpack/briefcase
System Overview: • User carries an RF Receiver • LCD Display • Piezoelectric Buzzer • Joystick Interface • Activate/Sleep/Deactivate Insert Receiver Picture
Transmitter Hardware • Atmel ATTiny2313 • Chipcon CC1000 Transceiver • Low Current Consumption • Small • Antennae Design
ATTiny2313 • Larger File Size • SRAM • Watchdog Timer • UART • Small package • SPI
CC1000 • Operating Frequency • Configuration • SmartRF Studio
Receiver Hardware • ATMega32 • LINX RXM-900-HP-II • LCD • Joystick
ATMega32L • Low Current Consumption • RISC Architecture • 32K Flash Memory • 1024 Bytes EEPROM • 3 Counters • Programmable Serial UART • Input Capture • 3 External Interrupts
LINX RXM-900-HP-II • Programmable Carrier Frequencies • Direct Serial Interface • No External RF Components • No Tuning Required • Easy Usage
LCD • Standard Hitachi HD44780 Driver • Small compact size • ~2mA consumption • Command Set
Joystick • Low amounts of board real-estate • Multidirectional Usage • Intuitive User Interface • De-bouncing
Receiver Scheme • Timer Interrupt Polls • Receives a Constant Pulse • Interrupt • Input Capture • Checks Pulse Width • Changes Frequencies
Batteries • 2032 • 2477 • Good Supply Voltage • Low Battery Profile • Reasonable Supply Curve • mAh
Problems and Solutions • ATTiny12 • Antennas and attenuation • RF Boards – Current Draw • Initialization of the CC1000 • Soldering the CC1000 • Doesn’t flash with components connected • LCD Initialization failure • LCD Buffer Circuit
Things to Complete/Further Work • Build multiple transmitters • Utilize a CDMA scheme to increase resilience to noise and free up channels • Implement a sleep/watchdog timer • Minimize package
Personal Reflections • NEVER try to fabricate your own boards for RF • Avoid prototyping with surface mounts • Multiply projected timelines by 4 as opposed to 2 • The best place to crash is the Sunny room
Conclusion • Good experience taking a project from scratch to close to completion • Learned to deal with group dynamics • Sleep is an option not a necessity
Thank You Questions
References • “Lost and Found.com: The Internet Lost and Found,” [Online Document] Available: http://www.internetlostandfound.com/ • “Lost Property Office - Statistics,” [Online document] Available: http://www.tfl.gov.uk/tfl/ph_lost-stats.shtml • “Survey: Thousands Leave Laptops, Mobiles in Cabs,” Jan. 24, 2005 [Online document] Available: http://edition.cnn.com/2005/TECH/ptech/01/24/taxis.lost.reut/index.html • “New Tube Crackdown Puts Pickpockets on the Run,” [Online document] Available: http://tube.tfl.gov.uk/content/pressreleases/0110/29.asp • “1551KGY” Image. http://www.hammondmfg.com/1551K2B.jpg • Smith, Kent (RFM). “Antennas for Low Power Applications”. Feb 8, 2005. www.rfm.com/corp/appdata/antenna.pdf • “Atmel SOIC” http://sub.chipdoc.ru/im/atmel/avr/2313_p.gif • “Atmel TQFP” http://www.epsilon.com.pl/img/at90s8515_tqfp2b_250.jpg • “TPA Navigation Tact Switch” http://www.ittcannon.com/media/pdf/catalogs/tpa.pdf • “HP Tx and Rx” http://www.linxtechnologies.com/index.php?section=products&category=rf_modules&subcategory=hp-3_series • “Peter Ouwehand.“How to control a HD44780-based Character-LCD. 2005. http://home.iae.nl/users/pouweha/lcd/lcd0.shtml • “2032” http://rocky.digikey.com/WebLib/Panasonic/Web%20Photos/CR2032.jpg