Disappointed to see that didn’t work. Have you got a phone, tablet or laptop charger knocking about which uses USB type C? They may be powerful enough to provide enough power, maybe even borrow one from someone else to try it out before committing to buy any more kit. I’ve used a Google Pixelbook 45W charger for a bit when messing about with various setups which seemed to work OK. I think you may need to make sure it supports Power Delivery.
HI, and thanks.
Must say it has been a most revealing couple of days, since I ran into this. Have been testing several setups. USB powered hubs, and SSD’s, even tweaked USB cables with cut Red (power) leads. All to no avail or final solution yet…
First: providing the Pi itself with more power than designed (3.0A) to allow the USB’s to drive power hungry devices makes no sense according to the design specs. No matter how many Amps you feed the Pi via its power slot, the USB’s are maxed at 1.2A together at all times. See:
https://www.raspberrypi.org/documentation/hardware/raspberrypi/power/README.md
which is the official doc I think we all should stick to.
As stated in that document, back-power is a risky business. Bypassing the voltage protection of the PI’s fuse is not a good idea… Not only that, (and this is not mentioned, but, in my case, the issue), allowing the USB to back-power the PI prevents the Pi from being booted (simply because it never gets cut from power).
So, first I tweaked the connecting cable, but this still won’t make the PI reboot with the Sabrent Hub. meanwhile I’ve also tested a TP-Link hub, of which I read it does allow the Pi to reboot. (or must say, the new version of the one mentioned…) Doesn’t even startup …!
The older version is also on its way, so maybe that will work.
For now, Ive hooked up the new (faster, larger, better ranked in your doc) Sandisk Extreme portable 500GB SSD directly to the Pi once again, and have seen no problem yet. No Idea of the power rating, for that isn’t mentioned on the device or the packaging.
To be continued… and on the quest for this most important paragraph in the doc you posted:
Make sure you get one that is compatible with the Pi as some powered USB hubs won’t work properly with it so check the reviews and do your research to make sure people are using it successfully with the Pi.
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for reference, (the above mentioned new SSD functioned fine, and no bricks happened, but nonetheless) I tested 3 USB hubs.
- the Sabrent mentioned in the posted by Ian: it allowed the Pi to startup, but no reboot host, probably because of back-power. However, even with a tweaked usb cable it wouldn’t reboot.
- the Tp-Link which is the modernized version of the one below. This one didnt even start the Pi… no idea why , but I immediately disconnected, because that feels really dangerous…
finally the
- Tp-link, which started up the Pi alright (…), but also allowed me to reboot the host! yeah… guess Ill leave the testing at that, it seems to be a well built Hub alright, with a single power button (no selectable ports like the Sabrent, but I dont need that)
all in all a mixed experience, of which I learned a lot.
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