Raspberry Pi Hat Kicad project
The pourpose of this project is to simplify Raspberry Pi HAT design by providing the source shematics and routing for a HAT compatible shield This refer to HAT design guide https://github.com/raspberrypi/hats
This GitHub repo is owned by Disk_91, see more detail on hat design in this post from my blog http://www.disk91.com/?p=1870