11

TUTORIAL

Build your own ANPR home automation setup

Automatically switch on the lights when your car is recognised parking outside your house

Build your own ANPR

home automation setup

A

Paul

Freeman-Powell

Paul is a technology

enthusiast, geek, video

producer, drummer,

cyclist, husband, father

to three children,

including twins, and host

of the award-winning

Switched On Network

YouTube channel. You

can find his website at

switchedonnetwork.com

@paulfp

utomatic number-plate

recognition systems (ANPR, or

ALPR / ‘License Plate’ for our

American friends) are used by the

police to spot cars of interest, and

by some car parks to record when

you enter/leave. We’ve always fancied building one

but, as we run neither a car park nor an international

crime-busting agency, there’s been little point...

up until now. In recent years, with the explosion

of the Internet of Things and the IoT’s integration

with cloud-based services for such devices, a world

of possibilities has opened up, and the price of

components has also become much more accessible

for the hobbyist, so that got my imagination ticking.

This project works by setting up an IP security

camera to point at your driveway, or the street outside

your house, at the spot in which you park your car. A

Raspberry Pi, connected to your home network, then

monitors the network stream from the camera and

passes the video through some free software called

OpenALPR, which spots and reads car number-plates.

A Python script then processes the results and any

number-plates found and, when it spots your car

number-plate arriving home, it communicates with a

smart WiFi LED bulb, via the IFTTT service, to turn the

hallway light on. When you drive your car away, the

reverse happens and the light is switched off again.

See the diagram overleaf to understand the program

flow and sequence of events.

There are a number of ways you can approach this

project. OpenALPR offers a cloud-based API where

your program can upload still images and return

results found. You can also choose to use their cloud

Right

Pi connects to your

home network with

an ethernet cable.

The indicator LED

connected via

a breadboard is

optional, but you

can use this same

concept to drive a

relay switch to do

other things, if

you like