Has anyone successfully managed to power both[nbsp] a Pi 4b and an official 7inch touchscreen? I am getting low-voltage warning, using the main USB output to power the screen.


12.06.21 17:16

Hi mirrormurr,

i would like to help you. However, I still need some information about your setup.

What power sources are you using?

If mUSB:
Are you using the official mUSB Raspberry power supply? If not, what kind of power supply do you use?
Do you use an adapter (e.g. USB-C to mUSB)?

Which USB port do you mean by main USB output? Do you mean the high-power USB A output of the StromPi 3?

Have you ever tried to power the display with cable jumpers via the GPIO connector? Does the problem exist there as well?

Best regards

Nils (Joy-IT)


15.06.21 13:39

hello again,

Took a while until I got the platina, battery and the Pi properly connected, but I am able to troubleshoot the issue now withhout interruptions.

I have tried different combos with offical and unoffical powersupplies rangning from 3 to 5 ampere, direct connections with no splitters or adapters and even a separate powersupply for the LCD-screen. The only options I havent tried out, due to the whole inconvenience with[nbsp] cables running from inside the case to the outside on the battery-pack,[nbsp] is to power the LCD via GPIO. Low-voltage is more or less constant. Am also using powerred USB-hub to avoid any drain on the ports.

The interface shows small fluxes on the microUSB around 5.10v, and output 4.9 to 5.0V, LifePo4 battery 3.333V.

Hope that will give some insight,

best regards,




23.07.21 21:01

Hello mirrmurr,

thank you for your message.

We just tested the StromPi in combination with the Raspberry Pi 4 and the original 7 inch touchscreen display.

We connected the micro USB-port of the display to one of the USB-ports of the Raspberry Pi. We could not find any problems concerning the voltage of the system.
It was always at around 5V. We experienced the same when we used the high power USB port of the StromPi.

Apart from that we also connected the display to the StromPi using the GPiO-pins. There was no voltage warning in this case either.

If the cables that are used are okay than it is likely a problem concerning the StromPi.

In this case we recommend sending the device back to your retailer to get a replacement.

Yours sincerely,

Niklas Tritschler

27.07.21 16:28

Dear Niklas,

Thanks for your thorough troubleshooting, it is good to know that every option has been properly tested. This is however my second StromPI platina, after having returned one with a slightly curved set of soldering-points of GPIO pins. Alas, when mounted,[nbsp] both show similar behaviour, so I guess the culprit have to be something in my powerchain that really isn't up to snuff.

I'll try to get hold of yet another power supply, mine are both from Sunnysoft, marked as official, but one might be fooled..



28.07.21 09:19

Hello mirrormurr,

thank you for your message. You are correct. If the behaviour can be observed with different devices, it is very likely a problem concerning the powerchain.

Yours sincerely,

Niklas Tritschler

28.07.21 10:50