Raspberry Pi 2/3 (B/B+) relay server with 2020 profile attachment points (e.g. for OctoPrint, home automation, etc.)

In creating a casing for my new Prusa i3 style 2040 aluminium extrusion printer (similar to or heavily inspired by an AM8) I needed to create a compact housing for both the Raspberry Pi 2/3 (B/B+) and the 4 channel relay I use.

The relay is controlled by several shell scripts to schedule certain GPIO ports of the Raspberry Pi from within OctoPrint. This way I'm able to switch the (older computer) power supply, schedule LED lighting and extruder cooler fan on/off.

The relay I obtained did