This is a controller that I'm using to remotely control an irrigation system for my garden. You, however, can use this to control any piece of hardware that can be supplied with 12VDC at a maximum power of 15.6W.

The controller box is designed to hold the following components:

-A Raspberry Pi 3A+.

-A Mean Well RS-15-12 12VDC power supply (to power the RPi and the relay bar).

-A Mean Well RS-35-5 5VDC power supply (to power external components).

-A 4 relay bar (https://mauser.pt/catalog/product_info.php?cPath=324_517_2118&products_id=096-7805).

-Cabling.

The models include the box, a wall mounting bracket, a lid (I made one out of acrylic but you can print it as well), and several caps that allow for screw access. The access caps are here to give easy access to the electronics screws whilst keeping the design compact (I printed this on an ender 3 pro).

The main step file also includes mock-up models for the electronics so, if you need them for your own projects, have at them.