Problems Encountered - Up to Midterm

1. Problems Encountered - Up to Midterm • State Machine Transitions Much Too Fast - Solved by Decreasing Clock (LED Circuit) • Difficult to Test LED (Column) Display Without Proper Band Filtering • NS16550 UART (Communications IC) Becomes Extremely Hot • Serial Communication More Difficult to Implement than Previously Expected

2. Other Problems Encountered…since Midterm • LCD – Idea abandoned after a week and a half of trying to get it to work • Needed more external hardware to fully implement it – OEM Version • Used for showing the band and its current dB level • Not Imperative – mostly for eye candy

3. Problems cont… • Alternate Solution? • Added another seven segment LED to show which band user is on (1-5) • Band’s current dB level displayed on the PC using the VB software • Hmmm…another problem? – No PC? • Would need to add some type of external memory element to store previous dB level – Future Group?

4. Problems cont… • Main Equalizer IC problems: • IC packaging not normal (legs closer together than regular TTL ICs • Hence…made a modification – Seen in Lab • Bought (2): • One does not work at all • Other one – through wear and tear, the input (audio signal in) leg broken off • Hence, No Testing • Waiting on New One to Arrive – On Order • All testing done using the Xilinx Simulator

5. What could be improved, perhaps next group? • Knowing what we know now, add a LCD component to display bands • Or add some type of memory element to store dB levels • Add battery to FPGA to store instructions (when powered off) – also makes it portable (Stereo Use) • Maybe a different UART? Makes communication easier

6. New (Approximate) Cost of Prototype • 50 LEDs ~ $15-$20 • Miscellaneous Driver Chips for seven segment/columnar LEDs (7) ~ $15 • FPGA Chip ~ (We think) $15 • Misc. Wires, Buttons, Capacitors, Resistors ~ $20 • Xilinx Software (FPGA) - ?

7. Costs cont… • 16550 UART IC ~ $10 • Equalizer IC ~ $12-20 (If Available) • Total ~ <$100 w/out Cost of Software Included…… • …Conclusion……much cheaper than originally thought

8. Andrew Nguyen’s Contributions • Fabricate the Hardware • Build State Machine for the Equalizer • Build the Circuit for the Equalizer • Test the Equalizer • Help Craig and Kevin

9. Craig Petersen’s Contribution • Developed Both a Hardware and FPGA Version of LED (Digital) Display (State Machine) - Displays Band, dB Level, Positive/Negative Sign, and decimal point • Developed LED (Column) Display Using 10 LEDs for Each Band • Helping Andrew Communicate with Equalizer Circuit - State Machine and Verilog Code for I2C Bus

10. Kevin Wong’s Contribution • Worked On Equalizer Control Software (PC - Visual Basic) • Wired-Up Stand-Alone FPGA • Built The Serial Interface Circuit • Implemented UART Control State Machine • Also helped Andrew and Craig

11. Nguyen Nguyen’s Contributions • Write code in Visual Basic to test on a loop-back cable. • Help around in making circuit board layout. • Figure out the pin number on Xilinx chip to connect to RS-232. • Using state machine to change the state of output frequencies.

12. In Summary… • 95 % Complete…Should be completely ready by demo time later this week. • Good experience in software and hardware integration • Learned to work as a Team to complete an objective