Remote Operated Audio/Video Switcher

1. Remote Operated Audio/Video Switcher

2. Team Members • Jordan Goulder, Leader • Joe Laszczak • Kian-Wah Chee • Dr. Harden, Advisor

3. Problems With Current A/V Devices • Low Cost Switchers • Little crosstalk prevention • Manually switched • High-End Receivers • High cost • Large size

4. Solution • Remote Controlled With Current Remote • Quality Output • Relatively Small • Reasonable Price

5. Objectives - Design • IR FrequenciesRC5 and RECS 80 • Signal Loss<10 dB at 10 MHz • Min. Input Voltage.667 mV (40 dB) • Input Frequency20 Hz to 890 MHz • Crosstalk56 dB at 10MHz

6. Objectives - Real World • Device Size3in x 4in x 1in • Cost $60 • Learning AbilityUser Programmable Remote Button • Reliability1 error per 1000 switches • FCC ComplianceFCC Code Part 15

7. Recent Redesign Issues • Added Functionality a. Option to assign random input assignments b. Increment or Decrement • Decrease Device Size

8. Infrared Receiver Status LED’s Learn/Reset Button Input Selector Buttons Remote Switcher User Interface

9. 1 2 3 4 X Controller 4:1 Audio/Video Multiplexer 4 RI 1-4 L/R Infrared Signal Internal Design

10. Major Design Issues • Correctly identifying RECS 80 and RC 5 infrared data transmission schemes • Effectively implement the functionality of the switching device through the controller • Minimize interference while maintaining small device dimensions

11. Controller Functionality Start Program Wait for Input Program Program Button1 Program IR Read IR Buttons… Program Button2 Buttons… Valid IR Program Button3 Evaluate IR Program Button4 Buttons… Program Button++ Output <= Input1 Output <= Input2 Output <= Input3 Output <= Input4 Output <= Input++ Output <= Input-- Program Button--

12. IR Demodulator - Output

13. IR Demodulator - Output

14. Crosstalk- Measured Results and Comparisons

15. Loss – Broadcast Frequencies

16. Software Testing

17. Power Consumption

18. Cost of Major Components

19. End of Semester Achievements • Successful programming of functionality • Successful infrared detection and decoding • Successful interaction of controller with RF components

20. Design Problems • Undesired RF penetration through multiplexer • Breadboard capacitance severely increase crosstalk potential • Undesired loss at low RF frequencies

21. Design Solutions • Change the switching method from 4 input mulitplexer to independent path feeding • Use PCB to eliminate board capacitance • Use high speed low noise op-amps to amplify low frequency broadcast channels

22. Prototype

23. References References: [1] Eugene R. Bartlett, Cable Television Technology and Operations HDTV and NTSC Systems, McGraw Hill Publishing Company, New York, New York, USA, 1990. [2] Wagner Lipnharski, “Infrared”, http://www.ustr.net/infrared/infrared1.shtml, UST Research Inc., Orlando, Florida, November 1999. [3] Gabriel Ricardo, Michael Vandegriend, Scott Medynski, “Infrared Codes for ConsumerAudio/VideoElectronics”, http://www.ee.ualberta.ca/~elliott/ee552/studentAppNotes/1999f/IR_codes/, University of Alberta, Alberta, Ontario, Canada, November 1999. [4] Crutchfield Home Theater Catalog, “Crutchfield Home Theater Catalog”, http://www.crutchfield.com/cgi-bin/S-a6A7XN37AYP/ProdGroup.asp?c=4&g=10420&s=0, Charlottesville, Virginia, September 2002. [5] Federal Communications Commission, “Part 15- Radio Frequency Devices”, http://www.access.gpo.gov/nara/cfr/waisidx_01/47cfr15_01.html, Washington, DC, 2001 [6] Rheinfelder, William A, CATV System Engineering Third Edition, Tab Books, Blue Ridge Summit, PA, USA, 1970.