Beginners • Re: Battery-powered RPI4

Code:

Name:   gpio-poweroffInfo:   Drives a GPIO high or low on poweroff (including halt). Using this        overlay interferes with the normal power-down sequence, preventing the        kernel from resetting the SoC (a necessary step in a normal power-off        or reboot). This also disables the ability to trigger a boot by driving        GPIO3 low.        The GPIO starts in an inactive state. At poweroff time it is driven        active for 100ms, then inactive for 100ms, then active again. It is        safe to remove the power at any point after the initial activation of        the GPIO.         Users of this overlay are required to provide an external mechanism to        switch off the power supply when signalled - failure to do so results        in a kernel BUG, increased power consumption and undefined behaviour.Load:   dtoverlay=gpio-poweroff,<param>=<val>Params: gpiopin                 GPIO for signalling (default 26)        active_low              Set if the power control device requires a                                high->low transition to trigger a power-down.                                Note that this will require the support of a                                custom dt-blob.bin to prevent a power-down                                during the boot process, and that a reboot                                will also cause the pin to go low.