Home Security

A smart home is a safe home. In this guide, we're going to take our cardboard smart-home and equip it with sensors to protect the home against intruders, wanna-be burglars, and invisible chemicals. 

What is the IO Home?

Interested in making your house a bit smarter?  Why not start small by building a Cardboard Smart Home! Adafruit IO Home is a series of learning guides covering all aspects of a smart house: from temperature monitoring to an intelligent home security system. 

Want to scale up from the cardboard home to a real home?  We've selected real-world components, sensors, and hardware which can also be installed in your home, office or laboratory!


Door Sensor

We'll be building a small front door (out of cardboard, of course) for our home. We'll use a reed switch and magnet to detect if the door is open or closed. We'll be adding a toggle-block on our Adafruit IO dashboard to arm/dis-arm the system.

Top view of magnetic contact switch with three screws.
This sensor is essentially a reed switch, encased in an ABS plastic shell. Normally the reed is 'open' (no connection between the two wires). The other half is a magnet. When...

Motion Sensor

We'll also utilize a PIR sensor to detect any intruders who hang out in front of our house after dark.

PIR (motion) sensor with a cable around it.
PIR sensors are used to detect motion from pets/humanoids from about 20 feet away (possibly works on zombies, not guaranteed). This one has an adjustable delay before firing (approx...

Air Quality Sensor

Now, what about the thing most people don't think to monitor? We're talking about invisible intruders - gasses and air particulates. While gasses and volatile organic compounds are already inside your home - you'd benefit from adding the ability to measure them. The SGP30 Air Quality Sensor is one of our favorite sensors - it can monitor both the amount of Carbon Dioxide and Volatile Organic Compounds in your home's air.

Angled shot of a Adafruit SGP30 Air Quality Sensor Breakout.
Breathe easy with the SGP30 Multi-Pixel Gas Sensor, a fully integrated MOX gas sensor. This is a very fine air quality sensor from the sensor experts...

Alarm System

 A piezo buzzer and a NeoPixel Jewel are used in this guide as a combination of visual and audio alerts to notify you when your home has detected an after-dark intruder.

1 x Piezo Buzzer
Small, but mighty, buzzer.
1 x NeoPixel Jewel
NeoPixel Jewel - 7 x 5050 RGB LED with Integrated Drivers

To use this guide, we'll need a microcontroller capable of connecting to Adafruit IO. The Feather HUZZAH with ESP8266 is used in most of our Adafruit IO Guides.

Angled shot of rectangular microcontroller.
Feather is the new development board from Adafruit, and like its namesake, it is thin, light, and lets you fly! We designed Feather to be a new standard for portable microcontroller...


You'll need these extra materials to assemble the home security system.

1 x Breadboard
Half-Size Breadboard
1 x Breadboarding Wire Bundle
You'll want some of these wires to hook up your sensors.
1 x Solder
Mini Spool, 100g of 60/40 rosin-core solder.
1 x Right Angle USB Cable
USB Cable which bends at a right angle, can fit easily inside the house.


Owning, or having access to, these tools will make this guide much easier to follow. If you do not have access to them, pick some up from the Adafruit Store.

1 x Ruler
Our snazzy PCB reference ruler. You don't need THIS ruler, but you do need a ruler.
1 x Helping Hands
Helping Third Hand Magnifier W/Magnifying Glass Tool
1 x Soldering Station
Hakko FX-888D
  • X-Acto Knife, Box Cutter, or Sharp Knife
  • Hot Glue Gun
  • Double Sided Tape

This guide was first published on Sep 05, 2018. It was last updated on Mar 08, 2024.

This page (Overview) was last updated on Mar 08, 2024.

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