https://hackaday.com/2014/09/09/adding-io-to-the-rasberry-pi-models-a-b/
The Raspberry Pi has been the basis for many cool projects. Even so, Models A and B have been criticized for having only a handful of GPIO pins available....
rasberry piaddingmodels
https://www.hackster.io/hartmut-wendt/din-rail-mount-for-rasberry-pi-zero-205a8c
How to use the RasPiBox Zero DIN rail enclosure kit to install your Pi0 based home automation or industry 4.0 project in a cabinet. Find this and other...
din rail mountrasberry pizerohacksterio