1. CS-EE 481 Spring 2007 1Founder’s Day, 2007 University of Portland School of Engineering Project Boring Authors Michael Braun Geoffrey Friason Eric Yost Advisors Dr. Aziz Inan Dr. Peter Osterberg Industry Representatives Mr. Wes Mickanin, TriQuint Semiconductor, Inc. Mr. Jared Hay, Intel Corp.

2. CS-EE 481 Spring 2007 2Founder’s Day, 2007 University of Portland School of Engineering Agenda Introduction Geoffrey Background Geoffrey Methods Eric Results Mike Conclusions Eric Demonstration Mike

3. CS-EE 481 Spring 2007 3Founder’s Day, 2007 University of Portland School of Engineering Thank You Dr. Inan and Dr. Osterberg Mr. Mickanin and Mr. Hay Ms. Sandy Ressel Dr. Mayer and Carl from the Physics Dept. AllegroMicro, Microchip, Analog Devices

4. CS-EE 481 Spring 2007 4Founder’s Day, 2007 University of Portland School of Engineering Introduction We need devices to detect and characterize magnetic fields for research and educational applications The solution is to create a device that –Outputs useful information –Is portable –Is accurate

5. CS-EE 481 Spring 2007 5Founder’s Day, 2007 University of Portland School of Engineering What to Watch For The key technologies –Hall effect sensors –PIC18F452 microcontroller The theory behind our device Test results in a 200-turn coil A video demonstration

6. CS-EE 481 Spring 2007 6Founder’s Day, 2007 University of Portland School of Engineering Background: Key Technologies Hall effect sensor PIC microcontroller LCD Analog multiplexer Analog-to-Digital converter Voltage regulator

7. CS-EE 481 Spring 2007 7Founder’s Day, 2007 University of Portland School of Engineering Background: Data Capture How data is captured: 5 points 3 sensors at each point

8. CS-EE 481 Spring 2007 8Founder’s Day, 2007 University of Portland School of Engineering Background: Data Capture Four types of data capture: Magnitude, XY-angle, XZ-angle, YZ-angle

9. CS-EE 481 Spring 2007 9Founder’s Day, 2007 University of Portland School of Engineering Background: Specifications ComponentValue Casing<10 lbs., 6”x6”x12” or smaller Strength of Magnetic Field0 to 180 Gauss, ±2 Gauss accuracy Response Time<5 seconds Power Supply+5 ± 2% Volts Analog-to-Digital Converter16-bit precision

10. CS-EE 481 Spring 2007 10Founder’s Day, 2007 University of Portland School of Engineering Methods: Documents Functional Specifications Project Plan Theory of Operations

11. CS-EE 481 Spring 2007 11Founder’s Day, 2007 University of Portland School of Engineering Methods: User Interaction ZERO/MEASURE button RESET button LCD

12. CS-EE 481 Spring 2007 12Founder’s Day, 2007 University of Portland School of Engineering Methods: Displaying Data

13. CS-EE 481 Spring 2007 13Founder’s Day, 2007 University of Portland School of Engineering Methods: Mathematics The ‘math.h’ library –Magnitude generation requires power, square root function –Angle generation requires arctangent calculation

14. CS-EE 481 Spring 2007 14Founder’s Day, 2007 University of Portland School of Engineering Methods: Improving Accuracy Averaging –Zero function requires 100 samples from each sensor –Measuring function captures a single measurement

15. CS-EE 481 Spring 2007 15Founder’s Day, 2007 University of Portland School of Engineering Methods: Testing Comparing the device with a Gaussmeter Using known fields 200-turn coil Speaker magnet

16. CS-EE 481 Spring 2007 16Founder’s Day, 2007 University of Portland School of Engineering Results: Architecture

17. CS-EE 481 Spring 2007 17Founder’s Day, 2007 University of Portland School of Engineering Results: Main Circuit

18. CS-EE 481 Spring 2007 18Founder’s Day, 2007 University of Portland School of Engineering Results: Firmware Data Flow

19. CS-EE 481 Spring 2007 19Founder’s Day, 2007 University of Portland School of Engineering Results: Power Supply

20. CS-EE 481 Spring 2007 20Founder’s Day, 2007 University of Portland School of Engineering Results Tested device with 200-turn coil Compared the difference between the Gaussmeter and device values

21. CS-EE 481 Spring 2007 21Founder’s Day, 2007 University of Portland School of Engineering Results TestMean Diff. (G)Std. Dev. (G) Front Left0.380.5541 Front Right0.360.5814 Center0.91.0724 Back Left-1.021.6589 Back Right-0.50.7583

22. CS-EE 481 Spring 2007 22Founder’s Day, 2007 University of Portland School of Engineering Conclusions Successful completion of functional specifications Created a useful, informative, displayable device Learned valuable lessons in the design process

23. CS-EE 481 Spring 2007 23Founder’s Day, 2007 University of Portland School of Engineering Video Demonstration Let’s go to the tape!

24. CS-EE 481 Spring 2007 24Founder’s Day, 2007 University of Portland School of Engineering Thank You. Are there any questions?