Overall Specifications

A project log for SquareTone

A hardware project that generates square waves frequencies and sums them together, Fourier style.

Adam GulyasAdam Gulyas 01/04/2016 at 04:380 Comments

This is somewhat a living document. It may change if a certain requirement is discovered to be difficult to implement and fails a cost benefit analysis. The next step is to use it to generate a block diagram of the proposed system.

Basic Purpose

Preform additive synthesis with square waves.

Sum square waves of arbitrary magnitude and output the result as audio, a synth control voltage, and a visualization of the resulting waveform. The square waves frequencies are multiples of a fundamental frequency. If the fundamental frequency is 100 Hz, the other available frequencies will be [200, 300, …, 800] Hz.

The output fundamental frequency range will be decided during the design phase. As a minimum it should cover [0.1, 100] Hz for use as a LFO. Ideally it should go up to 10 kHz, in order to cover the useful audio range.


Summary of Method

Generate an initial high frequency square wave and frequency divide it down to the desired harmonics. Sum the harmonics. Provide the ability to control the summing coefficients and invert individual harmonics to get a negative summing coefficient.

Currently I don’t know how to change the phase of each harmonic while still being able to optionally keep them in phase and at the correct multiples of each other (at least using analogue techniques).

Inputs Accepted

Outputs Available

User interface