GRBL, of course, runs on the Arduino, so the whole machine runs fine with normal G-code. This post will be especially interesting if you want to build a plotter or something similar.

“The pen plotter in question is a DIY machine that Oaks constructed using linear rails, stepper motors, and an Arduino Uno board with a CNC Shield that runs Grbl firmware. The computer connected ...

An interesting Arduino project has been published to the Instructables website showing how an Arduino CNC shield and controller has been used to create an awesome 3 axis Arduino CNC plotter.

Support for those had to be added to his Grbl_ESP32 firmware, as did dealing with the lack of homing switches in the plotter, and adapting the Grbl tool change command to the pen color change ...