Auto filter interface for C64 using Arduino

I have been recently enjoying the exquisite stuff that Sebastian Tomczak is posting through his little-scale blog, lots of cool chip-data-hacking action for your brain.

One of the latest is this great arduino based idea, a software / hardware combo that allows for control of the analog filter inside a Commodore 64 that is running Cynthcart from a host computer (eg, Macbook, PC).

Software
• 16-step filter sequencer
• Set the speed of the filter sequence (with intervals between values reaching 2ms)
• Set the length of the sequence from 1 to 16 beats
• Offset value allows for shifting the filter values up or down on a larger scale
• MIDI mode allows sending data directly to control the filter (this mode disables the sequencer)

The hardware is very simple, and is based around an Arduino board that is using a bit-banging SPI technique to write data to a 100KΩ digital pot.



//

so, to learn more, just grab the schematics, source code and all that > link

Ahoy!