So you already have an Arduino or an Arduino compatible board? Sweet, lets get you controlling Pd from that hardware! Here is a list of options to get started. These include a general tutorial as well as files to get you going with some specific boards.
Load the Sound Clippys firmware – this is set up to read in 12 digital inputs and 8 analog inputs. The instructions here are for the Sound Clippys board but will work for any Arduino – just substitute your board type when you download.
If you have one of these boards – just follow the instructions to learn how to use it with Pd.
PicoBoard – Uses the Scratch protocol to read the sensors
General Arduino and Pd tutorial – bi-directional communication between Arduino and Pd