How to Use a Magnetic Door Switch / Sensor With Arduino

In this tutorial we will use one magnetic - contact door sw / sensor and a buzzer for making a "noise" when a door is opened. Normally the reed is 'open' (no connection between the two wires). The other half is a magnet. When the magnet is less than 13mm (0.5") away, the reed switch closes.

Step 1: What You Will Need

For this project you will need:

• Arduino uno
• Magnetic Contact Switch - Door Sensor
• Buzzer
• Breadboard and some cables

Step 2: The Circuit

The connections are pretty easy, see the above image with the breadboard circuit schematic.

Step 3: The Code

Here's the code, embedded using Codebender!

Try downloading the Codebender plugin and clicking on the "Run on Arduino" button to program your Arduino board with this sketch. And that's it, you've programmed your Arduino with this sketch!

Step 4: Well Done!

You have successfully completed one more "How to" tutorial and you learned how to use a magnetic contact switch with Arduino.

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Comments

[shukriluccen]

instead of buzzer how i can send the signal to the smartphone?

[vledbetter1]

Does any one know if I could use the switch to power the arduino? My thought is a battery operated system so I am wanting a light and an audio file to play when the door is open. So I am hoping for battery conservation to only power the arduini when the door is open. I am thinking. Open door closes the circuit to the power source. If not, i know i can do an if statement with the switch but i can not find the idle battery consumption. Any ideas would be greatly appreciated.

[dannygeilen1710]

This is a late reply but try this 1
Door Sensor(Voltage MV Indicator) - Instructables
its based on an attiny85 battery powered

[KhineP]

what types of using magnetic Switch?

[OkaNare]

I need to change

int state; // 0 close - 1 open wwitch

to

int state; // 1 close - 0 open wwitch.

How do I alter the code? Please help.

This is for my wardrobe light. I just swapped the buzzer for an led.

[ArjunP49]

use PNP transistor for switching

[cpainy]

Thank you! Great tutorial.

Do you have any thoughts about how long the sensor wire can be?

[Codingpro]

Any length should work.