I build AV equipment for art galleries & installations. I use Raspberry Pi’s for video installs.
I’ve been using a shutdown button on a digital I/P for use before switching off the power. But this is a poor engineering solution. Often gallery staff don’t press the button, and just switch off stuff.
What I’d like is a small board where I can plug in a Li-Po for a controlled shutdown. I’ve found some UPSs that can be configured to do this, but they tend to be complex beasts, and therefore expensive. I’m looking for something of a comparable price to the RPi Zero that it’ll be protecting.
I’ve found a circuit that’s similar to what I want, but a) uses a 12V input, rather than 5V, and NiCads rather than Li-Pos. I like the digital output confirming that shutdown has taken place, but a timer is also okay:
This is something that I have been struggling with also. I live in a rural area of France where short but frequent power outages cause me a lot of grief with my Pi audio setup.
Take a look at this forum - https://volumio.org/forum/ There is some info if you search around.
Hi! If you want to safely shutdown your raspberry pi, open terminal and type: Sudo shutdown -h now . This is saying root user / super user, shutdown, halt the power, do it now!!
I think you misunderstand. There is no keyboard. There is no terminal. These are stand alone devices. I want shutdown on power removal. Ended up doing this with a supercapacitor circuit.
Well, the problem is solved, now. I’m using this sort of circuit, which shut’s down the Pi, prompted by a GPIO input, before the power from the supercapacitor disappears.
Well, I’ve still not found a pre-made board that does a clean shutdown properly. There are UPS boards, but none of them remove supply after shutdown, so the Raspberry Pi won’t boot up when the supply has returned, as, for the Raspberry Pi, it has never disappeared. There’s a nice output from Raspberry Pi, indicating shutdown is complete:
dtoverlay=gpio-poweroff,gpiopin=21,active_low
But not found a UPS board that uses this, to remove the power.
I have built my own using supercap, but thinking of using a Li-Po battery, instead. But I would really like to just buy them, as the need comes up quite often.