ifttt

Description

Using the If This Then That web service from the BBB to trigger crazy automated actions, such as interacting with Amazon Alexa, creating a Google Calendar event, or parking an Husqvarna Automower.

Description - Details

The ifttt program reads the room's temperature (or, in this case, generates a random one), and sends an http request to maker.ifttt.com if it's higher than 30°C.

For simplicity, I set up my ifttt.com account so that it sends me an email when it receives a request labeled high_temperature.

The ifttt program is automatically run by the linux cron daemon once per minute.

Build and Run

Refer to the top-level README for instructions on building.

Before running, open the .env file and adjust the variable IFTTT_KEY.

# (on the VM) sftp the executable and the .env file into the BBB
sftp-bbb
> put build/bin/ifttt
> put .env

# (on the BBB) run
./ifttt

The program will (of course) fail if you didn't set up a WebHook on IFTTT.com or didn't set the IFTTT_KEY env variable.

Setting up the Linux Cron Daemon

In the BBB, edit /etc/crontab so that it runs the executable every minute, and redirect stdout and stderr to a file:

sudo su
vi /etc/crontab

Add this line:

* * * * * root IFTTT_KEY=yourKey /home/debian/ifttt >> /home/debian/ifttt-logs.txt 2>&1

Here's a nice online tool that helps with cron schedule expressions.

Interacting with the SHT21 Temperature Sensor + Circuit

Instead of generating a random temperature each time the program is run, you could easily use the SHT21 sensor to measure the real one.
Check the i2c directory for details on setting it up.

Making HTTP Requests

The library cpp-httplib has greatly sped up the task of making HTTP requests.
It's been installed through Conan (check conanfile.txt and CMakeLists.txt for details).

What else is possible with IFTTT?

A ton of stuff, check https://ifttt.com/explore