11

Way Home Meter

TUTORIAL

To get a Telegram Bot token, download the Telegram

app on your phone and set up an account. Open the

app and press the search button on the top-right

of the screen. Search for ‘botfather’. Type /newbot

and follow the on-screen instructions. The botfather

will provide you a link to the bot and an access

token. The link is for the chat where people will

share their location; the access token is used in the

sketch to authenticate your ESP8266 as the bot you

just created.

Next, you will need to get a Google Maps API

key. Start by going to the following URL:

hsmag.cc/mPqFqh.

Check the Routes option and click Continue.

You will then be asked to create a project; you can

give this any name. You will need to add a billing

account, but this device will comfortably operate on

the free allowance given by Google. You will then

get an API token that can be used in the sketch.

And finally you will need to get your home’s GPS

location. A simple of way of doing this is using

Google Maps. Using a web browser (not the app),

navigate to your house on Google Maps and right-

click and click ‘Directions from here’. This will modify

the URL, which will now contain the coordinates

of your home; copy and paste these from the URL

e.g. 51.5546466,-0.2794867.

You now have everything you need to configure

the WayHomeMeter. Open up the WayHomeMeter

sketch and click on the config.h tab. First thing you

will need to enter is your WiFi details so that the

ESP8266 is able to connect to your WiFi.

Google maps gives a free monthly allowance of

credit – equivalent to 20 000 requests. That is just

under what’s required to send a request every two

minutes in a month (about 22 000). This device only

makes the request every two minutes that it is actively

monitoring someone’s home journey, so should stay

under the limit if used occasionally. It’s possible

this limit will change in the future. How often it

checks can be configured in the sketch by changing

delayBetweenGoogleMapsChecks.

GOOGLE BILLING

Above right

This is a custom

PCB that breaks out

all the pins of the

D1 Mini to screw

terminals, but it can

be easily recreated

with a standard

protoboard

Above

The address pins of

the LEDs should be

able to reach each

other without the

need for extra wire.

The power pins need

to be joined by wire

After installing these libraries, you should click

the ‘verify’ button (shaped like a tick) on the

WayHomeMeter sketch to make sure that

everything compiles fine.

SOME CONFIGURATION REQUIRED

You will need to make some configurations to get

this sketch to work for you, but you will first need

to get:

• Telegram Bot token


• Google Maps API token


• GPS coordinates of your home