Fatduino v2.0 = Analog monosynth/sequencer conrolled by Arduino

A new video of Fatduino v2.0 is uploaded to Youtube. This is an analog monosynth/sequencer based on a PAIA Fatman 2-osc monosynth, controlled by an Arduino mega. Version 1.0 had a cardboard "face", now it's mounted in an aluminium enclosure (but still spends a lot of time with its lid off!).

I've added loads of features which will be the subject of future videos, but until then here's a quick tour with notes and sounds:

Video is here: http://www.youtube.com/watch?v=BlcnRPIWn9Q&feature=channel_video_title

And source code is here, in Files section: https://sites.google.com/site/nibblernibbles/home

Nice work! Do you read parameters from the knobs into the mega or are they for tweaking post-mega?

I've got a twin-t ringing filter-style beatbox from a '70s organ I've been thinking of running from an atmega328p. I figure you can store 8 triggers per quantization step in a byte bitmask but I have to think about the right tradeoff on steps/bar and bars stored.

it looks like from your site you've been documenting this well. You might want to consider putting it on instructables.com, they often have contests with decent prizes.

Hi quarterturn

All of the small pots and buttons on the left are connected directly to the Arduino. The large pots and switches to the right are connected to the Fatman analog board and the stripboard with my mods on it.

The Arduino has control of the oscillator pitch voltage, the control voltage (used for filter cutoff, PWM and others) and the gate signals that fire the analog ADSR envelope generators. The control voltage results from a software mix between incoming MIDI note-on velocity, and a software LFO that may be MIDI-synced. So the Arduino decides what note to play and when to play it, and can affect the sound only through the control voltage. The actual sound waveform comes from the Fatman analog board.

You could try modifying my code to control your beatbox. Most of the user interaction at runtime in the Fatduino v2 now happens via the Avago display, which you wouldn't have. But there's lots of RS232 diagnostics which are enabled by sending a character to RS232. Then you don't need the display, but can test detection of midi note received etc. by looking at RS232 in the terminal window. Although you may find that starting from scratch is less of a tangle...

If you manage it, don't forget swing! It's simply the period modulation of the clock tick period (delay every second tick). I like this effect so much I dedicated a pot on the panel to it. It really transforms a mechanical beat into something more organic.

Thanks for the tip about instructables.com