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

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

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?

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

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

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) - ?

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

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

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

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

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.

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