devsfan1830
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Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Tue Aug 15, 2017 4:52 pm

Just setup my Pi 3 running OctoPi with the official touchscreen and through two different and well reviewed 2.5A, 5V adapters (canakit and a LoveRPi starter kit) I get the undervolt warning. I was under the impression that 2.5A was plenty to run the stock Pi 3 and the screen. Do I need an even bigger supply? Can anyone recommend one in the US? Running dual supplies (jumpers removed of course) makes it work perfectly but I'd like to simplify it if I can. I've tried it with the webcam and printer unplugged from the Pi so I know it is for sure the touchscreen. I also wonder if the issue might be a poor power delivery through the jumpers.

runboy93
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Re: Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Tue Aug 15, 2017 6:39 pm

Canakit should be 2.4A, but anyway strange problem. I have 5.1V 2.5A official power supply and never seen problem like this.

DirkS
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Location: Essex, UK

Re: Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Tue Aug 15, 2017 7:40 pm

Are you powering the Pi with the PSU and the screen using jumper wires from the Pi or the other way around?
The first method causes fewer problems.

SurferTim
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Re: Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Tue Aug 15, 2017 8:36 pm

I use a usb splitter with my 7" touchscreen. Works fine with 2.4A wall wart.
https://www.adafruit.com/product/3030

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elkberry
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Re: Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Wed Aug 16, 2017 6:25 am

I've also seen undervoltage warnings with the Pi 3B + 7" Touch LCD + 2.5A power supply when feeding the power to the display control board and through it to the 3B. This setup has too many connectors and thin wires in series. Also, the dedicated micro USB Y splitter cable from The PiHut/Adafruit causes also undervoltage warnings, so I won't recommend this either.

Simply wire the supply to the micro USB of the Pi 3B, then use jumper wires to power the display. I've got some Polulu empty sockets/housings 2x3 and 1x5 together with precrimped short wires and use them instead of the ones that came with the display, because the stock wires are excessively long.

See also photos here: https://plus.google.com/103555172011502 ... rb3QjC7PeE
From ZX81 to Raspberry Pi, but wait ... where's the 7805 gone?

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RaTTuS
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Location: North West UK

Re: Tried 2 new 2.5A supplys, still getting undervolt warning w/ Pi 3 + 7" touchscreen

Wed Aug 16, 2017 6:38 am

power PI from wall wart and the display from the Pi
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