The Input Plug is a small board containing a CD4067 16-channel analog multiplexer and a dedicated ATtiny45 to perform channel selection.
The 16 channels can be used as analog or digital inputs. They can even be used as outputs, with the restriction that unselected channels will be high-impedance (there is no output latching or buffering).
For additional details, see http://jeelabs.org/2010/04/28/meet-the-input-plug/
There is nothing to configure. The code running on the ATtiny45 can be found on the ip1.cpp sketch page.
The first batch of plugs (2010-11) was sent out with improperly programmed ATtiny45’s. The effect is that these run at 1 MHz i.s.o. 8. Here are the details and fix.
Dimensions: 21.1 x 22.9 mm
CadSoft EAGLE design files: see below.
This plug can be operated at 5V as well as 3.3V.
This board uses the conventions of a JeePlug and can be used with the ports on a JeeNode. It can also be used with other boards and MCU’s, if you hook it up properly and adapt the interface code for it.