Simple & Cheap Screen/Keyboard for Klipper (and maybe Marlin)

This is a basic screen and keyboard for Klipper (and maybe Marlin), for those who use Mainsail/Fluidd but would also like an inexpensive on-printer controller.

You only need an SSD1306 OLED screen and 4 tactile buttons, wire, and Dupont connectors. If you are going to use the temperature sensor as well, you need an LM75 sensor (or similar), a threaded insert, and an M3 screw.

There is an SSD1306 OLED screen panel and a keyboard panel. Both can be used as a cover for a 4040 aluminum profile, or used on the supplied base (which goes on the rails).

You can install both, or just one. They work independently.

Insert the SSD1306 OLED screen into the panel, being careful not to break the thin columns, then use a flame to melt the plastic and secure the screen to the front panel. They work like a rivet.

For the keyboard, use 4 6x6x5mm tactile buttons. Place the panel on a flat surface, insert the buttons and use a dab of epoxy to secure them in place. Solder one leg of each button to ground and the other to a wire going to a GPIO pin.

You can connect the screen/keyboard to your raspberry/sbc, or to your printer's mainboard if it has an i2c interface and free GPIO pins (EXP1/EXP2/etc).

I also included a case designed for the LM75 temperature sensor, but it also accepts other i2c sensors such as the BMP280. Use a threaded insert and a single M3 screw to secure the sensor. Connect the i2c interface in parallel with the OLED screen (and other sensors you have).

Included is an example .ini configuration file for klipper, for use with the Raspberry Pi 3b+. Change the pin definitions if you connect to another board. I know that Marlin supports OLED screens and keyboards, but as I'm not a user, I can't help with the configuration for it.

If installed inside a enclosure, print in ABS/PETG. Otherwise PLA is good enough. No supports nor brim needed, and any ‘standard’ resolution should work.