Beginners • Re: Safely turn off Raspberry Pi 4 Model B whilst not attached to a monitor

Code:

Name:   gpio-shutdownInfo:   Initiates a shutdown when GPIO pin changes. The given GPIO pin        is configured as an input key that generates KEY_POWER events.        This event is handled by systemd-logind by initiating a        shutdown. Systemd versions older than 225 need an udev rule        enable listening to the input device:                ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \                        SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \                        ATTRS{keys}=="116", TAG+="power-switch"        Alternatively this event can be handled also on systems without        systemd, just by traditional SysV init daemon. KEY_POWER event        (keycode 116) needs to be mapped to KeyboardSignal on console        and then kb::kbrequest inittab action which is triggered by        KeyboardSignal from console can be configured to issue system        shutdown. Steps for this configuration are:            Add following lines to the /etc/console-setup/remap.inc file:                # Key Power as special keypress                keycode 116 = KeyboardSignal            Then add following lines to /etc/inittab file:                # Action on special keypress (Key Power)                kb::kbrequest:/sbin/shutdown -t1 -a -h -P now            And finally reload configuration by calling following commands:                # dpkg-reconfigure console-setup                # service console-setup reload                # init q        This overlay only handles shutdown. After shutdown, the system        can be powered up again by driving GPIO3 low. The default        configuration uses GPIO3 with a pullup, so if you connect a        button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),        you get a shutdown and power-up button. Please note that        Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.Load:   dtoverlay=gpio-shutdown,<param>=<val>Params: gpio_pin                GPIO pin to trigger on (default 3)                                For Raspberry Pi 1 Model B rev 1 set this                                explicitly to value 1, e.g.:                                    dtoverlay=gpio-shutdown,gpio_pin=1        active_low              When this is 1 (active low), a falling                                edge generates a key down event and a                                rising edge generates a key up event.                                When this is 0 (active high), this is                                reversed. The default is 1 (active low).        gpio_pull               Desired pull-up/down state (off, down, up)                                Default is "up".                                Note that the default pin (GPIO3) has an                                external pullup. Same applies for GPIO1                                on Raspberry Pi 1 Model B rev 1.        debounce                Specify the debounce interval in milliseconds                                (default 100)