Raspberry Pi 4 case with 3.5" touchscreen

Case for the Raspberry Pi 4 with a 3.5" TFT display module. Enlarged holes around micro HDMI ports to facilitate cables with larger ends, adjusted positioning of port holes, and added a view slot so the PWR and ACT LEDs can be easily seen. Added airflow vents to help with cooling. The screen is raised slightly to accommodate the cooler I used (https://www.pishop.ca/product/dedicated-all-in-one-aluminum-cooler-for-raspberry-pi-4b-pwm-with-fan-adapter/).

This case holds the display slightly further from the Pi than where it would normally sit. This means that the screen's female headers don't push all the way down onto the Pi's GPIO pins, and about 1-2mm of the pins are left exposed. This means it may be possible to fit a shim PCB underneath to add connections for fan power, though I haven't tried it.

I used a display with fan power connections on its underside, and left the fan PWM control disconnected. It was a tight fit - the wires are short, and it was difficult to route them so that they wouldn't risk touching the fan during operation. If you decide to go the active cooling route, be aware that the case is a very snug fit, and there is no space to run wires underneath the Pi to solder onto the GPIO header from beneath.

The front piece of the case is held on using two 6mm M3 screws and two M3 nuts.

Four discreet holes in the case allow zip ties to be fed through along the bottom, making it easy to attach a power bank underneath the Pi for portable use. Link to the power bank I used, which has approximately the same footprint as the case: https://www.amazon.ca/dp/B07L933SN5. If you use a different one, make sure it's rated for 5V 3A output.

Some form of cooling is probably a good idea here. The Pi 4 tends to run hot, and even with the added vents, it'll get pretty warm under load without added cooling.