alicraigmile / pushthebuttond

A daemon process which listens to a GPIO port on your RPi, flashes an LED and runs starts jobs for you.

Push the button

My story

There's a lot of information online which I need to get at regularly in my job. And so I use pushbuttond running on a Raspberry Pi to quickly flip between information dashboards on a spare monitor at my desk.

If I quickly need to see the BBC Bitesize Kanban board ... I push the button.

If I then need to see the shaping board, or our audience stats, or our list of bugs (shh!) ... I push, push, push the button.

I'd love to hear what you use pushthebuttond for, so please get in touch with me. I'm @alicraigmile on twitter.

Cheers, Ali

Setting up the hardware

The button

Connect one side of a button to 3.3v, and the other to ground (via a 10Kohm resistor). Next connext the -ve side to GPIO17 (via a 1Kohm resistor).

The LED

Connect the anode of an LED (+ve end) to GPIO4 and the other end to ground (via a 60ohm resistor).

Installing

git clone https://github.com/alicraigmile/pushthebuttond.git
cd pushthebuttond
sudo ./install.sh 

Useful commands

Starting the service

sudo service pushthebuttond start

Stopping the service

sudo service pushthebuttond stop

Checking if the service is running

service pushthebuttond status

Starting the service on boot

sudo update-rc.d pushthebuttond defaults

Operating instructions

When the service is running, pushing the button will cause the job (default: loop-dashboards) to run.

When a job is running the LED will light.

When it completes, the LED will flash twice.

That's about it!

Changing the job which runs

You'll need to edit the pushthebuttond script to change the job which runs.

I've supplied a few different options:

• loop-dashboards - launch chromium browser in kiosk mode. A push of the button loops through a series of web addresses specified in the script (default)
• speak-the-time - um, it tells you the time.
• launch-xeyes - each push of the button adds a new set of eyes to follow you around the room

Troubleshooting

Testing the hardware

With the service stopped, run the script called blink to test the LED.

Check the logs

pushthebuttond has it's very own log file.

tail /var/log/pushthebuttond.log

Custom jobs

If you can write a shell script, and as long as it's somewhere sensible (e.g. /usr/local/bin) then pushthebuttond will be able to find it and run it.

Imagine the possibilities.

pushthebuttond could:

• Play you some music
• Tweet something
• Save a bookmark for you
• Take a photo from an attached webcam
• Tell your CI environment to start a build or deploy your website

What would you have it do?