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Topic starter
Hi,
I am trying to power my pi 4 with witty pi 4 with a uctronics POE splitter (this one UCTRONICS Gigabit PoE Splitter 5V 3A, 2-in-1 PoE to USB C/Micro USB Adapter, IEEE 802.3af/at Compliant 10/100/1000Mbps for Raspberry Pi 3/4, Security IP Cameras and More) (I need to save a plug socket at this location). If I plug the POE splitter into the pi directly it works, if I plug it into the witty pi it doesn't even flash the lights. I have tried disabling the low and high voltage settings in the witty menu. Is there anything else I can try or is this just not going to work?
Thanks!
Posted : 04/03/2024 3:01 pm
After plug the PoE splitter into Wittty Pi, you can use a voltage meter to measure the actual voltage between 5V and GND in the unpopulated header P2, so you know what voltage is actually delivered from the splitter to Witty Pi 4.
Posted : 04/03/2024 3:15 pm
Topic starter
I'll order a voltage meter and report back 🙂
Posted : 05/03/2024 9:28 am
Topic starter
Please see attached video, it's doing something very strange. If I catch it when the V is up it boots and stays booted, I guess there is some form of power negotiating going on with the witty that doesn't happen with the pi?
This post was modified 10 months ago 2 times by msage
Posted : 06/03/2024 7:50 pm
Topic starter
I don't seem to be able to upload an MP4 or GIF to this post... but the voltage meter basically cycles
5.27v, 2.08v, 0.04v, 0.00v, 5.35v, 5.27v, 2.08v etc
Posted : 06/03/2024 7:58 pm
Witty Pi does not do power negotiation, it requires stable 5V DC from the USB type-C connector.
The cycles you saw explains why Witty Pi doesn't work: Witty Pi needs stable 5V DC to work, and your splitter delivers something different.
Posted : 07/03/2024 4:05 pm
Topic starter
@admin Ok, so this is a bit nuts... Turns out it was an issue with the network cable, no idea why it was working with the splitter plugged into the pi. I've changed the cable and it's now delivering a good steady voltage. Sorry!
Posted : 07/03/2024 4:19 pm