CNC/3D printer Joystick controller

Hello Everyone,

This is a modified version of the original work of Arminth (see here: https://www.thingiverse.com/thing:3404797/files )

This thing is basically a remote control for either your CNC milling machine, or for your 3D printer.
You can move all axis, X-Y and Z, but also the extruder if you're using it for a 3D printer, which can be useful to quickly load or remove your filament.

X and Y are controlled by the left joystick. Z and extruder are controlled by the right joystick.
Pressing on a joystick will allow you to select different distance increments for movements, 0.1mm/1mm/10mm. Once a distance increment is selected, the corresponding LED will light up: green for 0.1mm, yellow for 1mm and red for 10mm.
You can easily change those in the firmware if you want to.

The four buttons on top have the following functions:
-Home all axis
-do a Z probe
-Reset coordinates
-Unaffected, so you can put anything you want there. To add a function you just need to add a