[SOLVED] USB Hub for Rpi 3, will it work?

I know this is not a specific OpenHab question.

Thing is, my Rpi 3B is starting to get rather crowded around the USB ports.
One Z-Wave dongle. One RS484<>USB dongle, and one external SSD drive. Soon I will be getting a Zigbee dongle as well which will go into the last available USB port.
Then I was wondering, should I buy an powered USB hub insted? And will it work?
As far as I understand, some bindings etc, one has to specify which USB port beeing used, (or am I wrong?). How to deal with this, when using a USB Hub?

Yes and yes. RPi is pretty sensitive to the quality of power supplied and in anything less than ideal conditions the RPi will struggle to power all of those USB devices on its own.

Not really how it works. On Linux you need to define which file in /dev corresponds to your device, but that is completely independent to which port the device is plugged into.

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Thx Rich…
Then I got it all wrong, again regarding Linux… I´ll never learn :slight_smile:
One USB Hub coming up soon! I would hate to see the Rpi struggle right now, as things are getting pretty complex.

Ohh, almost forgot… I have this spare Rpi3 B+ which is not in use atm. Do you happen to know if there is any difficulties around OpenHab and this “new” Rpi 3B+ ? I know I wouldn´t gain much exstra power, but I bought it, I might as well use it, I guess.

I know of no problems.

You might want to check on the back power issue with some hubs when connecting to the Raspberry Pi - see for example: https://www.raspberrypi.org/forums/viewtopic.php?t=58452

Thanks John…
I ´ve read something like that as well… And to be honest, I simply don´t get the grib. All powered USB hub´s with an uplink port, should not have a back-power at all on the uplink port, since it´s used for data only.
If however the USB Hub does have a back-power on the uplink port, (which in a principal matter is very wrong), the Rpi should have a build-in protection against back powering coming from ‘outside’. I doubt the Rpi have ever been constructed to be powered through the four USB ports, which make me believe it´s beeing protected from back powering.

If someone wants to feed the power to the Rpi from a USB Hub, they should use the only logical interface, which is the micro-usb on the side of the Rpi, where the Rpi´s power supply would normally go into. Any other aspect is simply wrong and should indeed be avoided, as it would for sure cause problems, and probably blow up the fuse/protection inside the Rpi.
I wouldn´t take the chance on this, as it really dont make any sense. Of couse I could spare a powered plug and a power supply, but thats the only reason for doing anything like this. And if I was taking the chance, I would be using the normal interface (micro-usb) on the side of the Rpi.

This issue is not really just about Rpi´s. This goes for any USB ports of any kind. PC´s are having the same issues, as they use the same USB standards as well. The only reason why this has become an Rpi issue, is because of the Rpi´s lack of power/minimum powered and unstable power supplies etc. Most PC´s has enough power to supply itself and feed the USB ports as well with at least 500mA.