Screenbutton

Purpose

This project allows you to add a button to your Raspberry PI which performs the following two functions:

• Switch backlight for thescreen on/off on a short press

• Shutdown Raspberry on a long press (2 seconds or more)

Installation

Simply download the binary from the releases page to your Raspberry.

Usage

Manual start

The tool takes one parameter, which is the BCM number of the pin that your button is connected to. For more details on this you can for example refer to pinout.xyz/, but there are plenty of pages out there on this topic.

For pin 26 you can start the tool with:

./screenbutton 26

Screenbutton has to run with root rights as no one else is authorized to write to the file controlling the screens backlight.

Setting up as a service

I have provided an example systemd unit file that can be used to have this file executed at startup and keep running.

You can find this in the systemd folder of the respository.

Note	I have made two assumptions when writting the service file, please read these carefully!

1. This service definiton expects to find the screenbutton binary in /opt/screenbutton/, if you prefer to use a different location you will need to adjust this.

2. The pin is configured to 26

To install the service copy the file to /etc/systemd/system/ on your Raspberry and run the following commands:

systemctl daemon-reload
systemctl start screenbutton
systemctl enable screenbutton

After you did this the service should start at every boot.