USB hub/Ethernet I/O box for Prusa MK3 w/ RPi Zero

The Prusa MK3S has a great OEM-looking solution for connecting a Raspberry Pi Zero using the pins directly on a PCB, giving it plenty of extra functionality while remaining an integrated package. However, things start to look messy as soon as you need to connect your printer to a wired network or if you need to connect a USB camera.

One option is to use an OTG USB dongle or even mount a USB/Ethernet HAT directly on the Raspberry Pi using pogo pins, but then you lose the OEM look, risk bending the pins or damaging the EINSY board.

Since the Waveshare USB/Ethernet hat also allows plain connection via USB, it can be placed out of the way from the Raspberry Pi Zero and mounted securely in a more accessible location as a standard USB dongle, only custom-designed to fit the Prusa MK3 frame.

Parts & installation instructions

• 1x Waveshare Ethernet / USB HUB HAT for Raspberry Pi (1x RJ45 & 3x USB 2.0)
• 4x M2.5x20mm bolts
• 4x M2.5 standard nuts
• 1x micro USB type B to micro USB type B (details below)
• 1x printed case
• 1x printed lid

The USB hat board should just fit into the bottom case. Apply the top lid, thread the screws from the top and secure the assembly with the nuts inserted in the bottom case.

In order to secure the hub to the printer's 3030 extrusions, first you'll need to remove the rear plate connecting the Y-axis motor to the extrusions. Once disassembled, just slide the box into the profile. It's designed to be a tight fit so it stays securely in place even when plugging and unplugging cables, so a solid push might be neccessary. Reassemble the back plate and the Y-axis motor.

The micro-USB to micro-USB cable

When connecting this hub to a Raspberry Pi Zero over USB, you'd need to use some kind of a OTG USB converter and a standard A-B USB cable, but to ensure the cleanest possible installation, a custom cable is recommended. I made mine by soldering two old spare micro-USB cables directly together and sizing it exactly to reach from the hub through the electronics box and into the Raspberry Pi.

Once completed, you can run the cable down the EINSY case along the board and out from the bottom where it connects cleanly into the hub.