Hello,
the atmega 328 controller can be used on a breadboard as a cost efficient ad converter. I developed this especially for a scratch project, bus as the sample code is in python it might be interesting for the python-world too.
The firmware supports ad conversion with 2 channels, event counter, frequency measurement and it records timing of ir-receivers.
See http://www.raspberrypi.org/forums/viewt ... 37#p537137 for a description.
Regards,
Gerhard