A cheap little circuit that reads 10 analogue controllers (8 knobs and 1 joystick). I built it for my neighbour Jens' portable keyboard project. It's using an ATmega88 and a 4051 multiplexer to get 10 analogue-to-digital converters. A standard MAX232 with some caps lets the ATmega88 talk to the serial port of the computer.
Attached is schematics, AVR firmware and a MaxMSP patch for testing.