Alex Eames has now finished his series of videos about the RasPiO Duino, the great little add-on board for the Pi that gives you an ATMega chip, breakouts and a prototyping area. The last video is all about reading analog signals, such as those from a light sensor, and feeding them back to the Pi over a serial connection. So, if you want to see how this board can be used for this purpose, take a look on YouTube.