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Build your own ANPR home automation setup

TUTORIAL

sqlite> BEGIN;

sqlite> CREATE TABLE anpr_cars(id INTEGER PRIMARY

KEY AUTOINCREMENT, car TEXT, isHome INTEGER,

lastChangeDate DATE, lastChangeTime TIME);

sqlite> COMMIT;

Finally, write an INSERT query to populate the table

with the data you’ll be using:

sqlite> BEGIN;

sqlite> INSERT INTO anpr_cars(car, isHome,

lastChangeDate, lastChangeTime) values(“PA11LFP”,

0, date(‘now’), time(‘now’));

sqlite> COMMIT;

sqlite> .quit

IF THIS, THEN THAT...

You’re nearly ready to run the script, but first it’s time

to set up the action(s) you want to happen each time

you park your car on your driveway. In my case, it’s

going to turn on the hallway light by my front door,

which is a TP-link WiFi-enabled smart light bulb

controlled by the Kasa app. Kasa is supported by the

IFTTT service, which will act as a bridge between the

Raspberry Pi and the light bulb by using webhooks.

To configure webhooks on your IFTTT account,

log in and click on My Applets, then Services. Type

‘webhooks’ in the search box, and then click on the

Webhooks icon that comes up. Click Settings in the

top-right corner and click Connect. This will generate

a unique URL for your account with a key which

authorises your script to use your IFTTT account. Copy

and paste the URL into your address bar to bring up

the instructions page, which briefly explains how to

use the webhooks as various triggers in Applets you

can create. Essentially the Python script will make a

POST request to the IFTTT servers, and specify an

{event} followed by the key which both associates the

action with your account and authorises the request.

Make a note of the key from this page, as we’ll need

it in a moment, but first we need to create the Applets

• one to turn the light on when the car arrives, and one
  to turn it off when the car leaves.
  Go back to your My Applets page and click on New
  Applet, then click on the big ‘+this’ to add your ‘if this
  happens...’ scenario. Type ‘webhook’ in the search
  field and click on the Webhooks icon that comes up.
  Click on ‘Receive a web request’ for the trigger and
  then type your event name. This must match the event
  name in the script exactly, so type in ‘car_arrived’
  (without the quotes) then click create trigger.
  Next, click on the ‘+that’ and search for ‘Kasa’.
  If you’ve not already connected your TP-Link Kasa
  account to IFTTT, then you’ll be asked to do so. For the
  action, choose ‘Turn on’ and all your Kasa devices will
  be available in a drop-down; select the device you want
  to turn on – in my case it’s Hallway Light. Click Create
  Action and then Finish. Then, do exactly the same and
  create an Applet with the event name ‘car_gone’ and
  set this to Turn off Hallway Light instead.
  Once that’s done, install the main Python script:
  sudo apt-get install git
  git clone https://github.com/paulfp/ANPR-Home-
  Automation.git

This will download the script into a new directory

called ‘ANPR-Home-Automation’ within the pi user’s

home directory. Once that’s done, open up the Python

script with the following command:

cd ~/ANPR-Home-Automation

nano anpr.py

Look for the line which sets the ifttt_webhook_key

variable, and paste in the key you noted previously:

ifttt_webhook_key = “__YOUR_IFTTT_KEY__”

Save and exit the file. You can now run the Python

script like this:

python ~/ANPR-Home-Automation/anpr.py

Above

Using the calibration

utility, you can

artificially adjust

the perspective of

the image which is

given to OpenALPR,

to make up for

less-than-perfect

camera angles

If you don’t already

have your smart WiFi

LED bulb set up and

working, you can

watch a quick video

guide on how to do

this at:

hsmag.cc/uhoCic.

QUICK TIP

You’re nearly ready to run the script, but first it’s

time to set up the action(s) you want to happen

each time you park your car on your driveway

”

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