Arduino Wireless GSM Security System




Introduction: Arduino Wireless GSM Security System

Hi, here i will show you my gsm security system i made, you should have some experience with electronics beforehand. Feel free to modify this project in any way you like. All parts are bought from

The reason its wireles is so you dont have everything right behind the door, so for security reasons, there is about 10m from sensor to gsm module.
It takes about 5 seconds, from door is opened, til i get a call.

What you will need:

x2 Arduino (i use uno)
x1 GSM/GPRS Shield (with SIM900 chip, most common)
x1 Unlocked SIM card without PIN
x1 Reed switch or reed module

x1 433mhz RF transmitter
x1 433mhz RF receiver
x1 Strong magnet (i use neodymium)
+ A lot of wire
Different sensor (PIR etc)

Virtual Wire

You can solder a wire to ANT on rf module like i have done to get better range

Step 1: Building the Transmitting Circuit

Now you will connect your transmitting rf module and reed switch to arduino number 1

TX module:
DATA > digital pin 10
VCC > 3.3v
GND > Ground

Reed module:
DO > digital pin 12
VCC > 5v
Ground > Ground

Step 2: Building the Receiving Circuit

Now, place your gsm module on the second arduino

Depending on your GSM module,
you will connect the RX module:
DATA > digital 9
VCC > 5v
Ground > Ground

I have included a picture of how to connect RX using the gsm module i have.
Links to products used:
GSM Shield

Reed Switch

433mhz RF modules

Note: The GSM shield requires power from a wall outlet

Step 3: Code

The gsm shield powers up when you power the arduino
I have included a 20 sec delay, so you have time to get out the door
And a delay so it waits 30 sec between calls

Transmitting code

Receiving code

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    2 Discussions


    4 years ago

    Transmitting code and receiving code not fount ?


    5 years ago on Introduction

    arm7 interfacing lcd and gsm with source code