In this project I will show you how to build a very simple security system for all kinds of rooms. It might be simple but still effective. It is based around an Attiny85 and uses a reed switch and a key switch as inputs to see whether an intruder has accessed the room. A buzzer will then notify you or other persons. Let's build it

Step 1: Watch the Video!

The video gives you all information to build this simple security system. But I will cover the most important steps again.

Step 2: Order Your Parts!

As always, you can't build stuff without the correct parts. Here is my material list with example sellers for your convenience:


1x Arduino Uno (as programmer for Attiny85):http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Attiny85:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Reed Switch:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Key Switch:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x IC Socket:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 12V Buzzer:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x BC547 NPN Transistor:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

4x 10kΩ, 1x 1kΩ, 1x 640Ω Resistor (1/4W):http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x 10µF Capacitor:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x 0,1µF(100nF) Capacitor:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Push Button:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x LM7805 (5V linear regulator):http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x DC Jack:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x PCB (striped) :http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Male Headers:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Female Headers:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Red LED 5mm:http://rover.ebay.com/rover/1/711-53200-19255-0/1?...


1x Arduino Uno (as programmer for Attiny85): http://amzn.to/1tZNXjZ
1x Attiny85: http://amzn.to/1qKReWK

1x Reed Switch: http://amzn.to/1oO2b5Q

1x Key Switch:http://amzn.to/1oO2jCh

1x IC Socket:http://amzn.to/1tZPcQ0

1x 12V Buzzer:http://amzn.to/1qKSkSx

1x BC547 NPN Transistor:http://amzn.to/1tZPWVq

4x 10kΩ, 1x 1kΩ, 1x 640Ω Resistor (1/4W):http://amzn.to/1A2KZzi

2x 10µF Capacitor:http://amzn.to/1tZRcrz

2x 0,1µF(100nF) Capacitor:http://amzn.to/PD2jZj

1x Push Button:http://amzn.to/1qKUxgG

1x LM7805 (5V linear regulator):http://amzn.to/1qKUGAC

1x DC Jack: http://amzn.to/1oO2b5Q

1x PCB (striped) :http://amzn.to/1qKV2Hy

1x Male Headers:http://amzn.to/1qKVg1p

1x Female Headers:http://amzn.to/1tZTmHV

1x Red LED 5mm:http://amzn.to/1qKVuWm


1x Arduino Uno (as programmer for Attiny85): http://amzn.to/1BGO7iD

1x Attiny85: http://amzn.to/ZixmOf

1x Reed Switch: http://amzn.to/1BGOBVM

1x Key Switch: http://amzn.to/1EgGOCf

1x IC Socket: http://amzn.to/1EgGTG0

1x 12V Buzzer: http://amzn.to/1oIFpu8

1x BC547 NPN Transistor: http://amzn.to/1EgHLdT

4x 10kΩ, 1x 1kΩ, 1x 640Ω Resistor (1/4W):http://amzn.to/1upkTo4

2x 10µF Capacitor: http://amzn.to/ZizN3p

2x 0,1µF(100nF) Capacitor:http://amzn.to/1yFH4KK

1x Push Button: http://amzn.to/1EgI7kI

1x LM7805 (5V linear regulator):http://amzn.to/1n69hVK

1x DC Jack: http://amzn.to/1rYWQNd

1x PCB (striped) : http://amzn.to/1vElUHb

1x Male Headers: http://amzn.to/ZiC1Qm

1x Female Headers: http://amzn.to/Z4IZId

1x Red LED 5mm: http://amzn.to/1yFI9lN

Step 3: Build the Circuit and Connect the External Parts!

Here you can find the schematic for the circuit. I also uploaded my layout for the stripped PCB. If you build it exactly according to my layout then the chances are higher that everything will work in the end.

And don't forget to make interruptions in the copper traces! Those are the yellow dots in the second layout.

If you managed to finish the circuit then go ahead and connect the external parts like the reed switch or the key switchto the main PCB. Use my picture of the PCB as a reference.

Step 4: Upload the Code to the Attiny85

Here you can download my code. Feel free to change it if you are not pleased with the functions. I used an Arduino Uno as a programmer. Check out my other videos to see how this works.

Step 5: Success!

You did it. Now you can protect your belongings a little better and feel safer.Feel free to check out my Youtube channel for more awesome projects:

You can also follow me on Facebook, Twitter and Google+ for news about upcoming projects and behind the scenes information.



<p>Hi</p><p>This project is what i need, in our building we get a lot of breakings in the past year at basement.</p><p>I'm a newbie at electronics, the problem i have is that the power in the basement is 24V, i have a lot of transformer of 9v &amp; 4.5v from 220v ...</p><p>Can someone advise me on a good and cheap method of using 24v and not 220v ?</p>
<p>You can use a simple and cheap step down converter.</p><p>If you set the voltage to exactly 5 volts, you can go without the 7805 voltage regulator and capasitors</p>
<p>Now no one will ever sneak up on me again!! XD</p>
<p>I used to install burglar alarms, and my first reaction to this was &quot;This doesn't need a microcontroller, just a couple of relays.&quot; Then I realized that the Attiny costs less than one of the relays.</p>
you wrote simple but i say wonderful project..creative idea..nicely done..

About This Instructable




Bio: Awesome Electronics Tutorials, Projects and How To´s
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