I design this board because I wanted to replace traditional limit switches used in my CNC, with something more stable.

The working principle is very simple: when a magnet comes close to the board, it changes the state of his conctacts. In order to do that, the board implements an hall effect sensor that has the following features:

• Precision: high sensitivity makes the sensor very reliable because it can offer repeatable measurement with low tolerances;

• Noise immunity: hall effect sensors, as opposed to standard mechanisms inside typical switches, can not be affected by vibrations, dust, light and so on, because they aven any moving part that may fail. In addition to that, they can't be affected even by electrical noise because of high treshold on detecting magnetic fields.

How they works? First of all, you must supply the board with +5V then, it turns on and it's ready to go. In working conditions there are two possible states:

• Triggered: a magnet is close the sensor;
• Untriggered: there is no magnet near the sensor;

Untriggered state is default state of the board: LIMIT pin and GND are connected together and the led that indicates the state stay ORANGE. When the sensor is triggered, the circuit between LIMIT pin and GND is open. Led turns RED.

For the connections, the sensor mounts standard 2.54 header male pin and has a 5mm diameter hole in the middle in order to easily mount it in place. It can fit pretty anywhere because it is only 3cm x 2cm!

Operating only commutating his contacts, the board works exactly like other switches, so it can be used instead them, in typical application like proximity switching, positioning, speed detection and so on. Furthermore, due to their logic levels, they are compatible with most controller boards for CNC and 3D printers and thus they can be used, rightly, as limit switches.

(Best with Limit Switches Filter, check it out!)

For more detailed information please check the datasheet attached. If you have any questions, feel free to contact me.

I usually ship to most common destinations but if you country is not on my list, please contact me for finding the best solution.