Polyphonic midi sound module

Polyphonic midi synthesizer

Ian Bullock, Jackie Lam

Jackie Lam and I created a simple polyphonic synthesizer module on a board with a PIC18F microcontroller and Xilinx Spartan 3 FPGA. While many hobbyist music generation projects only allow one simultaneous note to be played, using the modular nature of FPGA code we were able to easily achieve 8 notes of polyphony and could produce many more. We also implemented a basic attack/delay/sustain/release (ADSR) type filter for the note amplitude to provide a more interesting sound.

Overall the project was pretty straightforward, but one of the main challenges was making efficient use of the limited multipliers on the FPGA. Multipliers are used for scaling the amplitude of each of the notes, and careful switching of the multiplier inputs and outputs was required to reuse the same multiplier blocks for multiple note signals.

RGB LED lights

RGB LED control

Real time wireless control of RGB LED lights for ambient room lighting.
Tidal turbine

Tidal turbine

Generating small amounts of electricity from water motion.
Liquid nitrogen cooled wind tunnel

Ice detection

Novel sensing methods for ice buildup on aircraft heat exchangers.
Polyphonic midi sound module

Polyphonic synth

FPGA and PIC microcontroller based polyphonic MIDI synthesizer.
Low noise CCD readout board

CCD readout

Low noise analog amplification and digital processing of the signal from an astronomical CCD sensor.
Courtyard chess set

Courtyard chess

Large scale courtyard chess set.

© 2015 by Ian Bullock
Contact: ian.bullockGETRIDOFTHIS@yale.edu