Auduino

 

Auduino Release status: experimental [box doku]
Description	Simple Arduino based synthesizer
Author(s)	tiefpunkt

The Auduino is a small synthesizer, based on the Arduino. The only external components required are 5 potentiometers, and something to output the sound, such as a small speaker, or a headphone jack.

Hacks

Modify the scale

By default, the Auduino uses a pentatonic scale. That can be changed in the source. An external switch to change the scale during runtime would be awesome.

Below are the options, only one is executed during runtime.

 // Smooth frequency mapping
 //syncPhaseInc = mapPhaseInc(analogRead(SYNC_CONTROL)) / 4;

 // Stepped mapping to MIDI notes: C, Db, D, Eb, E, F...
 //syncPhaseInc = mapMidi(analogRead(SYNC_CONTROL));

 // Stepped pentatonic mapping: D, E, G, A, B
 syncPhaseInc = mapPentatonic(analogRead(SYNC_CONTROL));

Adding some if-clauses, dependend on digitial inputs might be a decent solution.

Delay

Here's an example on using a ring buffer as a delay: http://rcarduino.blogspot.de/2012/11/auduino-with-delay.html

Maybe that could be added as an option as well.

CV Inputs

Pots are ok, but with some automation, we could play songs. So the idea is to add CV inputs to all the 5 pots (0-5V), which allow to connect a sequencer. Also, a gate input of some sorts would be cool as well.

Adapt the Scales to 1V/Octave

On "old" analog synth hardware, 0-10V CV was used, with 1V/Octave. Not sure if the current scale reflects that, but it would be cool if it did, otherwise it might be wise to adjust this. However, in our case it would have to be 0.5 V/Octave

Line Level Output

By default, the Auduino outputs a PWM-signal between 0 and 5V. It might be an idea to adapt this down to line level, which according to the web is between -0.5V and 0.5V. So it probably needs some kind of bandpass filter and pad on the output. Maybe even a buffer?

Headphone out

Add a headphone output to the line output.

Links

• Audoino Homepage
• Audoino Step Synthesizer (includes a good explaination of what's actually happening inside the synth)