systemd-gpio

SYSTEMD-GPIO(5)

NAME

systemd-gpio - run commands when a button on a GPIO pin is pressed

DESCRIPTION

Use systemd to configure commands to run when a button attached to a GPIO pin is pressed, released, or held.

To configure a GPIO pin, create a file called /etc/gpio/N, where N is an integer pin number following the gpiozero pin numbering_ convention. 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 [e-mail]

ENVIRONMENT

| GPIO_PULL_UP | GPIO_ACTIVE_STATE | GPIO_BOUNCE_TIME | GPIO_HOLD_TIME | GPIO_HOLD_REPEAT

Button behavior. See the documentation for the corresponding constructor arguments of `gpiozero.Button`_.

| GPIO_WHEN_HELD | GPIO_WHEN_PRESSED | GPIO_WHEN_RELEASED

Commands to run when the button is held, pressed, or released, respectively.  See the documentation for the corresponding properties of `gpiozero.Button`_.

FILES

/etc/gpio/N

Configuration file for GPIO pin *N*, where *N* corresponds to the `gpiozero pin numbering`_. The file should be in the `systemd EnvironmentFile syntax`_ and may define any of the environment variables listed above.

HISTORY

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 The main difference is that we are using gpiozero_ rather than WiringPi_, because WiringPi is no longer maintained.

EXAMPLES

The following example configures GPIO 23 so that when it is pressed, it prints a message to all TTYs, and when held, shuts down the machine::

# /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

To activate the pin, run the following command::

sudo systemctl enable --now [e-mail]

.. _gpiozero: https://github.com/gpiozero/gpiozero .. _WiringPi: https://web.archive.org/web/20220405225008/http://wiringpi.com/wiringpi-deprecated/ .. _gpiozero.Button: https://gpiozero.readthedocs.io/en/latest/api_input.html#gpiozero.Button .. _gpiozero pin numbering: https://gpiozero.readthedocs.io/en/latest/recipes.html#pin-numbering .. _systemd EnvironmentFile syntax: https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html#EnvironmentFile=

SEE ALSO

systemctl(1), systemd.exec(5)