Beginners • Re: USB Y-cable

The simplest answer, if it is possible for you, is to get an official RPi 5V1 5A supply.

Right, that would be the easiest solution, however as I don't have the official PSU I wanted to see if I can just mess around and get it working somehow with what I already have

It's much easier to troubleshoot when you eliminate the possible (regularly proven) weak points. Cutting and splicing cables adds more weak points, instead of removing them.

The reason you have an issue with the other supplies is that they will not give the rated power at 5V, but only at a higher voltage. Unless the PSU has a 5V 5A mode, the Pi will only use the default 5V 3A, and will limit the USB current as you have found. Using `usb_max_current_enable=1` in the config file will only work if the supply can produce enough current in the first place, which it seems they can't.

Yeah, the chargers I have might not be able to give 5V 5A (but 3A at least), but I was under impression that `usb_max_current_enable=1` setting would still allow RPi to go beyond the 0.6A limit. I measured RPi powerdraw from the charger while inserting the USB HDD into it and at spin up it was not going above 1.1A altogether while maintaining healthy 5.08V. Meaning that there should be plenty still available?

I know the PSU discussions are quite boring since it was said a million times to get an official PSU, so I am not going to defend my pesky chargers haha. Just wondering how it works then

That configuration will raise the USB current limit. Are you sure you put the right thing (exactly) in the config.txt file in the right place?
By adding it, you are assuming responsibility for the PSU, promising your Pi that it will not run out of current when it allows 1A2 to the USB. If you are wrong, the Pi will crash and may corrupt the OS.

How are you measuring the HDD current and voltage? Unless you have professional equipment capable of catching fast peaks, it is quite possible that the HDD peak current is causing a short voltage dip, too short to see on a meter but enough to prevent correct operation. If you are measuring 1A1 the actual peak could easily be over 1A6 (in which case even an official PSU won't help).

But there is nowhere to provide power for the powered hub ...

Sorry, but don't get that!
powered HUB comes with its own PSU.

What David refers to is my original post where I mention that I don't have any extra power sockets that I could use. But anyway, I am not sure how would a powered USB hub help me?

A powered hub would ensure that the HDD can have 5V 3A (assuming the hub can supply 3A on that port), which should be enough. If you have a hub meeting that requirement, it would be worth trying as a test, if not a final solution. [EDIT: to acknowledge the reply above, posted while I typed.]

Does the HDD work on any other system you have? (If testing on a Windows system, do not accept any offers to format the HDD!)

Statistics: Posted by davidcoton — Thu Jul 11, 2024 10:18 am

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