1. Auto-chromatic Musical Instrument Tuner Craig Janus and Robert Schmanski Advisor: Dr. James Irwin

2. Presentation Overview Terminology Project Summary Functional Description Block Diagram Software Milestones & Critical Problems Future Work Progress Summary

3. Terminology Pitch / Fundamental Octave Tuning error Cents

4. Project Summary Determine pitch of note played Inputs- microphone, mode/power switch, and pitch selector Output- pitch indicator, analog and digital tuning meters, and speaker 8031 microcontroller

5. Functional Description Inputs –Microphone –Power / mode switch –Pitch selector

6. Functional Description (cont.) Outputs –Pitch indicator –Analog tuning indicator –Digital tuning indicator –Speaker

7. Functional Description (cont.) Operating modes –Off –Auto tune –Manual tune –Audible reference pitch

8. Block Diagram

9. Overall Flowchart Table Look-Up Subroutine Software

10. Fundamental Determination –Typical Musical Waveform input: Milestones and Critical Problems

11. Input Conditioning Hardware –Schematic: Milestones and Critical Problems

12. Peak Detector Circuit –Schematic: Milestones and Critical Problems

13. Peak Detector Circuit –Critical Problem - Switching Noise: Milestones and Critical Problems

14. Peak Detector Circuit –Switching Noise Solution - LPF: Milestones and Critical Problems

15. Peak Detector Circuit –Solution Results: Milestones and Critical Problems

16. Complete Input Hardware –Response to Vocal Pitch: Milestones and Critical Problems

17. Complete Input Hardware –New Problem: Milestones and Critical Problems

18. Frequency Divider –74294 Programmable divide by 2^n Minimum divide of 2^2 –Need 2^1 to tune zero octave Milestones and Critical Problems

19. Manley Board Difficulties –External Interrupt –Port 1 Priority on Stand-Alone Microcontroller Hardware and User Interface Hardware Milestones and Critical Problems

20. User Interface –Component Selection 16 vs. 7 Segment LED displays Zero Center Analog Meter –Interface Simplification Pitch and Octave Up/Down Buttons vs. Rotary Switches –GAL for Address Decoding, Display Drive, and Button Debouncing

21. Future Work Original Design –Automatic Octave Selection –Improve Accuracy –Other Modes (Manual Tune, Reference Pitch) New Ideas –Automatic Gain Control –Improve Resolution

22. Progress Summary Peak Detector 2^n Frequency Divider GAL Usage Stand alone microcontroller hardware Student Research Exposition Auto Tuning Mode –9 octave range (1-9) –User selected octave Tuning Accuracy –1 cent at A4=440 Hz –5 cents at ends of table range Auto-chromatic Musical Instrument Tuner Craig Janus and Bob Schmanski Advisor: Dr. James Irwin, Jr.