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jplegat
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RPi 4 - USB-C drive support while running on PoE?

Thu Feb 13, 2020 8:57 pm

Hi,

Is there support or is it possible to connect an external USB drive to the USB-C port while powering the RPi4 via PoE? I’ve tested it on the regular USB ports and it worked. Does the USB-C port supports data as well or it’s designed for power only?

Thanks!

JP

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davidcoton
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Re: RPi 4 - USB-C drive support while running on PoE?

Fri Feb 14, 2020 12:10 am

It supports data but only to the USB2 spec.
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thagrol
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Re: RPi 4 - USB-C drive support while running on PoE?

Fri Feb 14, 2020 3:41 pm

There are a couple of potential issues but, yes it should work:
  1. While I don't have the link, if memory serves one of the power saving changes made for the 4B was to disable that USB controller by default at boot so you may need to mod your config.txt to enable it. Use the dwc driver for host only, dwc2 for slave.
  2. The ID/sense pin that's present on the micro USB connector (on zero(W)) is not present on the 4B's USB C socket so no automatic mode switching. You may also find that due this you need to force the mode (host or peripheral) in config.txt
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drgeoff
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Re: RPi 4 - USB-C drive support while running on PoE?

Fri Feb 14, 2020 3:44 pm

davidcoton wrote:
Fri Feb 14, 2020 12:10 am
It supports data but only to the USB2 spec.
The USB-C port on a 4B defaults to device mode .viewtopic.php?t=246348

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jplegat
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Re: RPi 4 - USB-C drive support while running on PoE?

Sat Feb 15, 2020 12:10 am

Thanks a lot for all the replies! The dtoverlay :idea: viewtopic.php?t=246348#p1504269 works like a charm.

For reference and if anyone is interested, here's a picture of the setup and links to the components.
IMG_6510.jpeg
IMG_6510.jpeg (83.81 KiB) Viewed 105 times
UCTRONICS PoE HAT for Raspberry Pi 4
https://www.amazon.com/gp/product/B082Z ... le_o07_s00

StarTech.com USB C to SATA Adapter
https://www.amazon.com/gp/product/B0133 ... _title_o03

SanDisk Ultra 3D NAND 500GB Internal SSD
https://www.amazon.com/SanDisk-Ultra-NA ... B072R78B6Q

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