Clean shutdown using a UPS

Usually the operating system is required to shutdown in order to avoid data loss and a corrupted OS. Often this is neglected and the power is just cut by removing the power cord from the photobooth.

Following is a recommendation how to implement a UPS. The features of the reference setup are:

• automatic power up when the power cord is connected to the photobooth (auto power on)
• automatic shutdown on unplugging the power cord by power loss detection
• cut power when shutdown finished to turn off the UPS protecting the batteries and save power

Reference setup

You tested another setup? Please tell us all the details so we can add the solution here!

Software setup

Geekworm X728

Power Management Integration

There is no need to use the custom Geekworm software at all. Just set the following parameters in the OS config.txt.

[all]
# Settings for Geekworm x728 v2.5
# cut power after shutdown
dtoverlay=gpio-poweroff,gpiopin=26,timeout_ms=6000 # early x728 versions is GPIO 13
# shutdown automatically on power loss detected, wait 3s before shutdown.
dtoverlay=gpio-shutdown,gpio_pin=6,active_low=0,gpio_pull=down,debounce=3000
# report battery status from x728 to the OS
dtoverlay=i2c-sensor,max17040

Realtime Clock Integration

Useful for all Raspberry Pi's <=4. The Pi 5 has an integrated realtime clock, so it's easy to use. Just put the battery.

[all]
# Settings for Geekworm x728 v2.5
# hardware clock
# remove fake-hwclock package when enable following line to activate RTC use.
dtoverlay=i2c-rtc,ds1307

In current bookworm system this should be all whats needed. Earlier OS versions might need more tweaking, follow the Geekworm Wiki for more details.