The mixing board is an interesting instrument. The combination of faders, buttons, and rotary knobs with tactile feedback and the abstraction of signal routing and summing result in a complex and expressive interface. The mixer is so compelling that many of its physical controls have carried over into digital audio workstation software. Some of these carry-overs make sense- but try controlling a rotary knob with a mouse and you'll see that many of them fall short.
Midi control surfaces offer a good bridge between analog consoles and digital audio software, but are prohibitively expensive and offer no sonic advantage on their own. So begins the challenge!
I used the Raspberry Pi for a few projects in 2014- it's an awesome little Linux computer that you can hack without risk, and it's got plenty of GPIO pins to connect random electronics. With some slight modifications it's possible to get the Raspberry Pi to send messages to any MIDI-capable device.
Since completion of the intial prototype, several OSC-enabled control surfaces have hit the markets. I look forward to seeing how these evolve!