Lemontron’s official software stack is Mainsail OS on a Raspberry Pi.

Prepare the SKR Pico

Install a jumper on to the BOOT pins on the SKR Pico (located in the center, under the “TE”in “BIGTREETECH”). Then, hold down the BOOT button and connect the SKR Pico to your computer. Drag this firmware file to the PICO drive that appears. Remove the jumper. Good to go!

Prepare the Raspberry Pi

Burn Mainsail OS via Raspberry Pi Imager onto your SD Card, ensuring you’ve added your SSH key and WiFi settings.

Use SSH to access the Raspberry Pi’s terminal and paste this:

sudo apt update && sudo apt upgrade
cd ~/klipper/
make menuconfig

In the menu interface that appears…

  1. Change microcontroller architecture to RP2040
  2. Change communication interface to Serial
  3. Save Config
  4. Run make in the terminal

Configure Mainsail OS

  1. Open up the Raspberry Pi webpage by navigating to the network name of the Raspberry Pi in your browser. If you named your printer “lemontron” then your URL would be http://lemontron.local
  2. Update everything!
  3. Click on the “Machine” tab (the last one) and upload the config files.

Install AutoHotspot

AutoHotspot is a script that will automatically switch your Raspberry Pi between WiFi and Hotspot mode based on the presence of your home network. Check out the AutoHotspot documentation for more information.