Magnetic Contact Switch Sensor with Arduino.

Magnetic Contact Switch Sensor with Arduino.


A reed switch is an electromagnetic switch used to control the flow of electricity in a circuit. They are made from two or more ferrous reeds encased within a small glass tube-like envelope, which become magnetized and move together or separate when a magnetic field is moved towards the switch. The switch effectively works like a gate, or a bridge, in an electric circuit so when the two reeds are in contact, electricity can flow around the circuit operating a device. Unlike mechanical switches they do not require something or someone to physically flick them on or off, they are controlled completely by invisible magnetic fields.


This video will show you how magnetic contact switch sensor works and simple project that can be made using it.

Hardware Preparation

This is the hardware connection and the components needed.

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Figure 1 : Hardware connection.

Sample Code


References :

  1. What is a reed switch and which magnets operate them?

Thank you

Thank you for reading this tutorial and we hope it helps your project development. If you have any technical inquiry, please post at Cytron Technical Forum.