[octotoad]

"or connect it to an arduino"

As the article mentions, this doesn't seem to be as easy as it should/could be.

[icebraining]

Connecting a RaspPi to an Arduino:

1. Get USB cable

2. Plug USB cable to Arduino

3. Plug USB cable to RaspPi

Steps 2 and 3 can be reversed.

[makomk]

4. Curse broken USB drivers

[ul5255]

not Arduino but close ... http://jeelabs.org/2012/09/20/serial-hookup-jeenode-to-raspb...