How to Make a DIY Smart Home Security System With Arduino

Making your own DIY smart home security system with Arduino is an excellent way to save money while creating a customized system tailored to your needs. An Arduino-based security system allows you to monitor sensors, control devices, and receive alerts - all without paying monthly fees.

What You Will Need

Here is a list of components I used for my Arduino smart home security system:

• Arduino Uno - The brain of the system. This microcontroller board allows you to program behaviors.

• PIR motion sensors - Detect movement and send signals to the Arduino. I used 3 around my home's perimeter.

• Door/window sensors - Detect when a door or window is opened. I installed 2 on entry doors.

• LCD screen - Displays status messages and sensor data. I used a 16x2 LCD.

• Buzzer - Makes an audible alarm when a sensor is triggered.

• LED lights - Visual indicator lights. I used 1 red and 1 green.

• Resistors - Current limiting resistors for the LCD and LEDs.

• Jumper wires - For making connections between components.

• Breadboard - Allows easy prototyping and connections.

• 9V battery - Portable power source for the system.

Setting Up the Arduino

The first step is assembling the Arduino board and connecting the components. Here is how I set up my system:

• Install the Arduino IDE on your computer and connect the Arduino Uno via USB. This allows uploading code.

• On a breadboard, connect the LCD screen, buzzer, LED lights, and resistors according to the pinouts. Refer to diagrams online.

• Connect the PIR sensors, door/window sensors, and any other sensors you are using.

• Connect the 9V battery to power the Arduino and components.

• For wireless capabilities, add a WiFi or Bluetooth module. I used a basic NRF24L01 transceiver for Bluetooth communication.

Programming the Arduino

Next, you need to program the Arduino to monitor the sensors, trigger alarms, and display status messages. I recommend the following code structure:

Include Required Libraries

At the top, include Wire, LiquidCrystal, and any other required libraries. This makes functions available.

Initialize Constants

Define sensor pins, LCD pins, LED pins, etc as constant variables for easy reference later.

Setup Function

In the setup, initialize the LCD, set pin modes, begin serial communication, and initialize any sensors.

Main Loop

The main loop continuously checks sensor states and triggers appropriate responses like sounding the buzzer, turning on LEDs, and writing to the LCD. Use if-then conditionals and boolean logic to take various actions.

Supporting Functions

Write additional functions for initializing specific sensors, displaying sensor data on the LCD, sending text alerts, etc. Breaking code into reusable blocks makes debugging easier.

Mounting the System

Once the electronics are functioning, mount the components for permanent installation:

• Place the Arduino, breadboard, and battery pack in an enclosure. I used a small plastic toolbox.

• Mount PIR motion sensors high in corners of rooms for wide coverage. Point them at entryways.

• Place door/window sensors on frames using adhesive or screws. Align the magnets properly so they are triggered when opened.

• The LCD screen, LED indicators, and buzzer can mount anywhere that is visible. I have them in my bedroom for easy monitoring.

Using and Enhancing Your System

With the basics set up, add features to customize your DIY Arduino security system:

• Add a wireless keyfob to arm/disarm the system when entering or exiting.

• Implement an alarm delay timer to give yourself time to disarm before sounding.

• Encrypt Bluetooth communication between sensors for security.

• Program an automatic sleep mode to conserve battery at night.

• Build a web interface to control the system and view sensor logs.

• Integrate voice control through home assistants like Alexa.

By leveraging the versatile Arduino platform, you can create a DIY smart home security system with exactly the features you need. Start with the basics in this guide, then expand possibilities - the options are endless! Let me know if you have any other questions.