Pi Zero UPS HAT (SKU: DFR0528) not keeping system alive - basic connection questions

markus.sand 2020-11-23 04:12:33 2601 Views4 Replies
Anyone out there who really got the UPS HAT working?

Tried to use it on a Pi2 Model B, but it will not keep the power up after I intentionally unplug the PSU.

So the first basic question is:
How should the DFR0528 supply power to the Pi2? Via the GPIO connectors?
Because I can´t measure 5V at Pin 2 or 4 of the DFR0528 if unconnected (Pi2 disconnected, PSU disconnected, Lithium battery connected and fully charged).
Or how else?

Second question:
How should input voltage be supplied to the Pi2/DFR0528 composition?
Micro-USB of Pi2 or Micro-USB of DFR0528?

Third question:
If I connect the DFR0528 to the Pi2 (Pin1 to Pin1), and connect the PSU only to the Pi2, I am not able to reliably read the values of the battery with the script from the Wiki (https://wiki.dfrobot.com/UPS%20HAT%20fo ... %20DFR0528).
Most of the time, I´ll get a "[Errno 121] Remote I/O error" reading the bytes.
If I do connect the DFR0528 to the PSU, too, then reading the values works reliably.
BUT: If I remove the power cable from the Pi2 then (simulating a power drop, or lets say, dusk in a solar powered environment), it will encounter a hard power off. This is exactly what the HAT should avoid, right?
So any hints what I´m doing wrong here?

Sorry, but I couldn´t find the answer to my questions in the Wiki (maybe they´re there, but I cannot read between the lines well enough)

I´m a little lost here, so will be thankful for any hints

Also, the mentioned Wiki contains some confusing typos and errors - and I´m obviously not allowed to edit there. So whom to contact to ask to correct them?

2020-12-07 05:45:08 So the solution for my issue was to press the button for 2 seconds. This will turn _on_ 5V power supply to the PI from the HAT. (unfortunately, it is turned _off_ by default, which I consider a really bad choice for the default.)

Also, according to the description in https://wiki.dfrobot.com/UPS%20HAT%20fo ... %20DFR0528, the switching on and off should only work for firmware version/revision 1.1 - where the HAT I have has "V1.0" printed on it.

So, anyone interested in improving the documentation here a little?

My questions now are:
- what are the real differences between V1.0 and V1.1?
- what board do I have now? 1.0 or 1.1? How can I find out for sure?
- if V1.0 really has no possibility to switch 5V on and off, I hope the default is "on" then, because otherwise the HAT would be completely useless?
- how can I order an old revision 1.0 then?

My use case is the following:
Use a Pi zero to provide data from a solar power plant. Use the UPS HAT to make sure the Pi can shut down properly at sunset (power is cut off).

This use case cannot be fulfilled with the UPS HAT I currently have, as unfortunately, when the current returns, the HAT is again at state "5V off" (therefore: bad default). And no-one will go to the solar power plant every day and push that freaking button. markus.sand

2020-12-01 19:02:32 Thanks for the information jennyreed1995

2020-11-27 04:21:56 Well, thanks for your answer, but it is not really helpful.
If you read my question again, it does say "Lithium battery connected and fully charged".
And the mentioned lithium battery I use is a 3.7V lithium battery, I could observe it getting charged, and I could read the values of the battery via GPIO as also mentioned above.

Any hints if we assume those preconditions are valid? markus.sand

2020-11-25 15:20:04 UPS HAT is a module that powers the Raspberry Pi through a lithium battery.
https://www.dfrobot.com/product-437.html
It has an interface that can be used to connect a 3.7V lithium battery and a lithium battery welding point. It cannot supply power by itself. Its USB interface can charge the lithium battery.
All the problems you are currently experiencing are due to not connecting the battery 347945801