This is a case for the Joystick Shield v1.a with an arduino UNO. The box makes it easy to send commands to your MPCNC (Marlin). You can find the code here: https://github.com/klalle/Marlin_Joystick . It may require some adjustments in the corners of the screen, but generally it works as expected. A STEP file of the CAD model is also included so you can make changes if you wish.