There's a different project for Raspberry PI 4: https://www.thingiverse.com/thing:4197636
Do not use Pi 4 version of this panel, it's incomplete, I've designed it using rpi4 model and the real rpi4 doesn't fit!

Front panel for Prusa i3 mk3/s extended to accommodate hyperpixel 4.0, raspberry pi 3b+, and a buck converter.

I've been using waveshare 3.5" screen for over a month, it has some advantages like price, and using only 10 GPIO pins but hyperpixel is so much better. It's more resposive 60fps vs 5fps, better colors, and better touch sensor. The active sceen size is on the other hand only marginally bigger 50,8mm x 72,9mm waveshare vs 52mm x 86,2mm hyperpixel.

Video of assembly: https://youtu.be/QUwxVzrvBoA

Check out the cable management clip: https://www.thingiverse.com/thing:3877011
4 should be sufficient for one side.

Last changes 25.10.2019

• Raspberry pi 4 not compatible - I'll update the project when I upgrade to rasp4.

Older:

• Changed both supports square nut hole size by -0.2mm that way the nuts won't fall out by themselves.
• Changed Right (Hyperpixel) support for tighter fit 0.2mm of extra space instead of 0.5mm

Install notes:

• Tighten the back plate screes very carefully. There's only 0.1mm of extra space for the screen and raspi combo, it may be not enough if your printer isn't well calibrated.
• Print back plate with 0.2mm layer height as there is a sacrificial layer for the screw holes.
• Slide the left support from the right side until it touches the pins. The right support should be easy to install.
• Hyperpixel screen uses all GPIO ports, or almost all if configured with smaller color space, so you can no longer connect the prusa printer using gpio, use usb port instead.
• The screen and raspberry is a thick combo, It'll not allow printer to be placed on a flat surface, It must stick out a bit.
  I resolved this issue by placing my printer on a marble brick with screen hanging off the front (this highly reduces printer noise)
• I recommend a minimum of 3A step down converter for powering raspberry pi, the screen and a camera, but this project will be compatible with pololu D24V60F5 (6A) and D24V90F5 (9A) because I like its quality.
• Buck converter box should be printed in pet/petg the extra strength is needed for the flexible ears.

If after installing the drivers the touch panel seems hugely miscalibrated do the following:

• Flash a clean image to the SD card - uninstalling the drivers don't always work.
• Copy git for pi3/pi4 or other:
  git clone https://github.com/pimoroni/hyperpixel4.git -b branchname
  where branchname is one of available on this site: https://github.com/pimoroni/hyperpixel4/branches
  -Install the drivers with:
  cd hyperpixel4
  sed -i 's/touchscreen-size-x\ =\ <800>/touchscreen-size-x\ \= <480>/g' src/hyperpixel4.dts
  sed -i 's/touchscreen-size-y\ =\ <480>/touchscreen-size-y\ \= <800>/g' src/hyperpixel4.dts
  sudo ./install.sh

Thanks to bolsoncerrado for pointing this!

Things to do:

• Add led switch box + I2C port extender