Main router USB port...


  • Bit of an off the wall question.... I have a headless/no peripherals Raspberry Pi that I want to co-locate next to my router; my router's PSU goes via a UPS (along with Modem & other critical devices, so no spare UPS power sockets). Just occurred to me that the router has a USB port (labelled 'reserved for future use'?) that could perhaps be used as a power source for the Pi - but thought it best to ask a couple of questions before plugging anything in (and maybe causing a hardware issue on router)...

    • does anyone know if the USB is currently active (as it's 'reserved for future use')
    • if active, presumably it delivers minimum USB power - ie 500mA..? Or more?
    • anyone else happen to have used the USB port to power an external device?

    Or - just don't do it...! ?

    Thanks.


  • @pawhe955 It has been stated that by support that the USB port on the HD is for Tech Support use only and will never be for use by users! I suspect it's the same for the Gamers Edition. I wish support would put a notice somewhere that tells current and potential users about the USB port!

    The "for future use" statement is misleading, therefore the question keeps getting asked!


  • Hi @pawhe955 - AmpliFi was never willing to confirm how many milliamps the port could supply, but @UI-Brett did report he powered a CloudKey from one

    But it’s unsupported so use it at your own risk


  • @pawhe955 : In my experience, RPi boards (most of my experience is with RPi3/3+s) will need more than what most (non "C") system provided USB ports can deliver in order to function properly and it's safest to make sure you use an actual power supply for them. The actual power needs vary by model, you can find them here: https://www.raspberrypi.org/documentation/hardware/raspberrypi/power/README.md#:~:text=Power Supply Product , 330mA 7 more rows ... While the "typical" bare-board active current consumption (which is what would compare to your headless/no peripherals) listed is less than 500mA in most listed (except for Rpi4), you could find your RPi system shutting down/rebooting on you sporadically because it just happened to need a little more power for a moment.

    For reference, while it's doesn't list the "typical" consumption, CloudKeys (both Gen1 and Gen2) list 5W (5V/1A) as their power requirement.


  • @oscartoro many thanks for the detailed reply. For the moment I think I'll not use the router's USB port - the Pi isn't that important so I'm currently powering from a spare USB on a Dell PC base unit - no reboots so far, and even if it does (and even if OS gets corrupted) I can easily re-image...


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