Limit Switch Module (Normally Open)

This module is great for multi-axis computer controlled machines like 3D printers. They are most often used for “homing” a machine’s gantries so the controller knows its position. End stops are another name for these as they are most often placed at the end of each gantry. These limit switches take very little force to push in, and have a roller on the end of the lever to protect the surface it will rub against. There is also a built in pull-up resistor and status LED for easy incorporation into your projects. Note that this limit switch module is wired as normally open, which means the circuit will remain open until triggered.

To read the switch, simply connect 3.3V-5V to the + pin, GND to the – pin, and an I/O pin on your development board (like an Arduino UNO) to the D pin. When the limit switch is pressed in, the LED will light up and the D pin will go low. When the limit switch is not pressed, the LED will be off and pin D will go high (to whatever the voltage is on the + pin).