systemd-gpio

Use systemd to configure commands to run when a GPIO button is pressed on a Raspberry Pi.

This project is inspired by https://github.com/ali1234/systemd-gpio. The main difference is that we are using gpiozero rather than WiringPi, because WiringPi is no longer maintained.

Usage

To configure a GPIO pin, create a file called /etc/gpio/N, where N is an integer pin number following gpiozero's convention. For example, to configure actions for pin GPIO23, create the file /etc/gpio/23.

The file should use the systemd EnvironmentFile syntax. All variables are optional.

The values for GPIO_PULL_UP, GPIO_ACTIVE_STATE, GPIO_BOUNCE_TIME, GPIO_HOLD_TIME, and GPIO_HOLD_REPEAT are passed to the Python gpiozero.Button class.

The values of GPIO_WHEN_HELD, GPIO_WHEN_PRESSED, and GPIO_WHEN_RELEASED control the commands to be executed when the button is held, pressed, or released, respectively. See the corresponding methods gpiozero.Button.when_held, gpiozero.Button.when_pressed, and gpiozero.Button.when_released, respectively.

Once you have populated the configuration file, activate the button by running the following command, replacing N with the pin number:

sudo systemctl enable --now gpio@N.service

Examples

# /etc/gpio/23
GPIO_HOLD_TIME=5
GPIO_WHEN_PRESSED="wall 'Hold the power button for 5 seconds to power off.'"
GPIO_WHEN_HELD=poweroff