Equation Composer

Welcome to the Equation Composer code. For general usage, or instructions on adding your own equations, modules, or synths, see http://www.microbemodular.com/products/equation-composer. If you'd prefer to jump in and start reading the code, try EquationComposer.ino.

In most cases, the code is grouped by file prefix.

• EquationBank[..] files contain equations that are used for the equation playback (bytebeat) style synths.
• Global[..] files contain global data used throughout the code. These are often 'const' data types, meaning that they're stored in the Arduino Due's program memory. Also, see defines.h.
• Module[..] files define the building blocks of the synths.
• Synth[..] files "wire together" the modules and produce the sound. Synths are selectable via the PRG knob on the EquationComposer.

Let's take a look at a sample synth:

SynthWavetableDelay.cpp:

SynthWavetableDelay::SynthWavetableDelay(Inputs* inputs)
{
	// Create modules
	ModuleWavetableOsc *wavetable_osc = new ModuleWavetableOsc();
	ModuleDelay *delay = new ModuleDelay();

	// Wire up the wavetable oscillator
	wavetable_osc->wavetable_input  = inputs->mod;
	wavetable_osc->frequency_input  = inputs->sr;

	// Put the wavetable oscillator through a delay
	delay->audio_input = wavetable_osc;
	delay->mix_input = inputs->param1;
	delay->feedback_input = inputs->param2;
	delay->length_input = inputs->param3;

	// Output the audio of the delay
	this->last_module = delay;
}

This is a typical synth. Here, the audio of a wavetable synthesizer is being sent into an audio delay, then output. This synth is composed of two modules, the ModuleWavetableOsc and ModuleDelay.

Documentation explaining what each synth does is located in the synth's .h file. For example, SynthWavetableDelay.h contains the following documentation:

// =============================================================================
//
// Name: SynthWavetableDelay
// Type: Audio
// Written by: Bret Truchan, 2014
//
// Description: A wavetable oscillator put through a short audio delay.
//
// SR - Sample rate of the wavetable oscillator
// MOD - Wavetable selection
// [1] - Mix (dry/wet) of the delay effect
// [2] - Delay feedback
// [3] - Delay buffer length
// GATE - not used
//
// =============================================================================

To learn more about each module, see the module reference. Alternatively, each module's .h file contains documentation explaining the module's inputs and outputs, along with sample code for using the module. For example, ModuleDelay.h contains the following documentation:

/*
* +----------------------+
* | ModuleDelay |
* |----------------------|
* > audio_input |
* > mix_input |
* > feedback_input |
* > length_input |
* | output >
* +----------------------+
*
*/
// =============================================================================
//
// ModuleDelay is an extremely short audio delay effect with control over
// mix, feedback, and buffer length. All inputs should range from 0 to 4095.
//
// Example usage:
//
// ModuleWavetableOsc *wavetable_osc = new ModuleWavetableOsc();
// ModuleDelay *delay = new ModuleDelay();
//
// wavetable_osc->wavetable_input = inputs->mod;
// wavetable_osc->frequency_input = inputs->sr;
//
// delay->audio_input = wavetable_osc;
// delay->mix_input = inputs->param1;
// delay->feedback_input = inputs->param2;
// delay->length_input = inputs->param3;
//
// this->last_module = delay;
//