All Arduino shields should have a standard Arduino footprint. 4 headers – The amount of pins on the headers depends on whether your shield has the newer R3 footprint, or the original Arduino layout.

Well, the PiMagic has female headers in the typical Arduino layout. This way any Arduino Shield will plug right in. [Steve] made all his source files available for those who want to make one ...

Now that a bunch of I/O are available, how do you physically access them? Well, the PiMagic has female headers in the typical Arduino layout.