Very simple limit switch breakout for DIY CD ROM 3D printer, plotter, etc. Connect 5v and ground to corresponding pads if you want the arduino pin to be pulled to ground when the switch isnt engaged, or reverse the polarity if you’d like it to be pulled high(the latter is the better option). the wires from each switch to the two switch pads, then the extra pad to the right of the switch pin to the arduino digital input pin you’re using for each switch. the fourth switch can be used to detect if filament has stopped extruding or run out and halt the process, or in my case as a second axis switch. of course if you want switches on either end of each axis you can use two boards and 6 digital pins