Reed Switch with Arduino

Reed Switch, also known as magnetic switch, is a type of sensor that works using a Reed system, a technology invented in 1936 by the Bell Telephone Laboratories, and it consists basically of a metal lamina that reacts when exposed to a magnetic field.

Figure 1 - Reed Switch and Arduino Uno

To use this sensor in your projects with Arduino, have at hand:

• 1x - Arduino
• 1x - Reed Switch
• 1x - 10KR Resistor
• 1x - Maginet (For tests purposes)

Figure 2 - Circuit Build

The connection is very simple, just connect the Reed Switch in series with the 10KR Resistor (it protect and ensure the pull-down on the signal), and between the two components, connect a wire to any Arduino digital pin, see Figure 2. That is all, just compile and upload the code that follows, and test.



For concrete purposes, usually Reed Switches are NO (Normally Open), check this information as well as minimum sensitivity range of the magnetic field.