Prusa’s GPIO module is a great tool for modders, hackers, and tinkerers who like to add new features to their 3D printers. This module connects to the I2C port on the xBuddy board of your Original Prusa MK4/S, MK3.9/S, or MK3.5/S printers and allows you to control and receive inputs from external devices.

You can create a trigger for your camera to capture precise photos for time‑lapse videos, control external LED lighting that alerts you with different colors when the printer finishes a print or requires attention, regulate fan speed, control servos, activate enclosure features, and much more—it’s up to you! All you need is the connected GPIO module and a custom G-code command that can be executed at a specific layer, at the start or end of a print, or on other events. All commands can be set directly in PrusaSlicer.

You can also integrate a button or macro keypad and assign specific G-code scripts to each button, stored on the printer’s USB drive, allowing you to control various printer functions, such as setting the printer to a ready state, managing prints, adjusting temperatures, or performing other actions.