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Comment by regularfry | Hacker News Reader

I don't think it's possible for the pi to also act as a host on its other USB port if you do this, is it?

One of the unfortunate things about the Raspberry Pi Zero is that the second micro usb is power only. For this type of configuration I encourage all to check out the Allwinner ARM-based SoCs and boards built from friendlyelec. With the NanoPi Neo I was able to enable USB ethernet gadget mode on its micro-usb and then have it host and power another device on its USB-A (for me a mobile phone). In my use case the laptop powered both the NanoPi and charging the mobile device all from USB power while also acting a an ethernet packet router from the mobile device back to the laptop all over USB on its own subnet.

https://www.friendlyelec.com/index.php?route=product/product...

Yeah, anything based on H3/H5 SoCs will work fine for this use case due to the SoCs having 4 separate USB host controllers, one of them muxed with OTG controller. That's a lot of I/O flexibility.

I ran out of ports on the usb charger I was using to run my little cluster so I have a couple of the lower power devices daisy chained off of the higher power ones.

It does mean that some devices will power off unexpectedly when others restart but unexpected restarts are something you have to plan for anyway.

Many clones have two usb ports, with one being OTG capable. For example the mango pi mq.

You should be able to do this with a pi 4, since the usb-c power port is also the gadget port. The usb 3.0 ones off the pcie bus on the pi should be completely independent from that and still work (not sure about the 2.0 ports or anything).

Oh, now that's interesting. Not quite the form factor I had in mind, but worth proving an idea or two out on.

Thanks.

Yep, and if that does work for you, then you might be able to get closer to the form factor you want using a CM4. That said you'd have to learn how to design your own board for it and potentially handle the pcie lane. But that would be a much smaller starting footprint with it at least.

FWIW - I was able to do this using a pocketbeagle. We even did this for a small run product where Octavo SIP exposed USB Serial and Ethernet via gadget, and then was a host on the USB1 side.

Seems true unfortunately, though you can at least switching between the modes somewhat convenient: https://forums.raspberrypi.com/viewtopic.php?t=282649

Yeah, not quite what I'm after. I want usb microphone into usb gadget. Bit of a pain that getting audio in takes an extra hat otherwise.

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