36 Sine Synth
36 : Sine Synth
- Author: R. Timothy Edwards
- Description: Keyboard synthesizer with one octave of notes and a sine wave generator
- GitHub repository
- Open in 3D viewer
- Clock: 50000000 Hz
How it works
This project implements a (trivially simple) music synthesizer, where "keys" are mapped to the input PMOD bits, and the synthesizer engine generates sine waves for each note. The sine wave generator is similar to the one that Mike Bell created to demonstrate the audio PMOD, but implements a more efficient method using delta steps. The 8-bit output is passed directly to the output PMOD, and simultaneously passed through a PWM generator (the one from Mike Bell's project) to drive the audio PMOD. I am considering recasting this as an analog project and adding an 8-bit RDAC, but this version is digital only. Output of the synthesizer is monophonic.
How to test
Preferably attach the 8 bits of the input PMOD port to a row of 8 buttons that can be played like a keyboard. Only whole steps are represented, for one octave C to C.
External hardware
Preferably use Mike Bell's audio PMOD on the bidirectional PMOD port. The project uses bit 7 as a single-bit PWM output that is used according to the instructions for the audio PMOD.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | Key C | 8-bit Output, bit 0 | |
| 1 | Key D | 8-bit Output, bit 1 | |
| 2 | Key E | 8-bit Output, bit 2 | |
| 3 | Key F | 8-bit Output, bit 3 | |
| 4 | Key G | 8-bit Output, bit 4 | |
| 5 | Key A | 8-bit Output, bit 5 | |
| 6 | Key B | 8-bit Output, bit 6 | |
| 7 | Key C | 8-bit Output, bit 7 | PWM Output |