USB issues (probably current limitation)


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I've been trying to connect a USB hdd for a while now, and depending on the SATA disk and the USB<->Sata adapter I've had different behaviours :

* 700mA hdd

  * Adapter A works, can mount and copy

  * Adapter B is detected, the SATA device too in dmesg, but does not appear in lsblk.

* 1A hdd (Seagate Barracuda 2To 2.5'')

  * Adapter A seems to be detected, the disk tries to start (sde is showing in dmesg) but usb device disappears, reappears etc ("usb disk bootloop")

  * Adapter B is not even detected in dmesg or lsusb !

 

Obviously, the 4 configurations perfectly work on a x86 host.

 

What could be going on ? I'm pretty confident this is a USB current limitation. I'm buying a USB-A + USB-A -> USB-C cable to power the disk from an external source too, will see if that helps.

 

If that's the case, this current limitation is HIGHLY PROBLEMATIC, please fix it in a future revision of the board ;)

 

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Armbian is a community driven open source project. Do you like to contribute your code?

I just received my USB power meter AND an usb splitter.

 

* With the usb splitter + an external power supply, the 1A hdd WORKS FINE ! This is REALLY a usb power issue.

* The power meter tells me the HDD draws 400mA idle. So... I don't even have the advertised 900mA.

 

@kobol guys, any help on that ?

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1 hour ago, Salamandar said:

The power meter


tells you nothing about the issue you are experiencing.

 

FYI:

1 hour ago, Salamandar said:

@kobol guys, any help on that ?


BTW. They are not responsible for every issue you (think) you find in hardware or in software. Linux is a community project per se! We do it together and we as a developers community help them that they can deliver you this nice device in best possible manner. Without our help ...

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@SalamandarYou cannot do anything without compromising the integrity of the motherboard as it is a hardware limitation and it is announced in the product description (remember 900mA/port USB-A) so there are no surprises here.

 

Its true that it will be very practical (although not necessarily vital) to have a USB-C DAS 3A on the front of the device (Pine User, Hub, HDD, ..) for next gen. 

 

Sometimes I am using my USB-C 11in1 Hub with USB-C to USB-A adapter on the front port of the unit and my Hub is powered by the power charge input with my power supply of smartphone 5A.(Native function at the same time : Eth 1G, SD, USB3x3 / USB2x2; not fonctional : Jack3.5mm, VGA and Hdmi). 

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6 hours ago, Salamandar said:

* With the usb splitter + an external power supply, the 1A hdd WORKS FINE ! This is REALLY a usb power issue.

* The power meter tells me the HDD draws 400mA idle. So... I don't even have the advertised 900mA.

 

Your power meter won't be able to catch current spike during disk spin-up because the spike is very short. But most likely the spike is high enough to trigger the over current protection.

So yes with the current design you will need a dual USB type A cable to get enough current for hungry HDD.

 

For next revision we will increase current limit on one of the port to address external HDD which requires more than the standard 900mA.

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On 3/12/2021 at 12:14 AM, Igor said:

BTW. They are not responsible for every issue you (think) you find in hardware or in software. Linux is a community project per se! We do it together and we as a developers community help them that they can deliver you this nice device in best possible manner. Without our help ...

That's not a Linux issue here, but a hardware issue. The hard drives run fine with armbian on a rpi3b+ ;)

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On 3/12/2021 at 5:27 AM, gprovost said:

 

Your power meter won't be able to catch current spike during disk spin-up because the spike is very short. But most likely the spike is high enough to trigger the over current protection.

So yes with the current design you will need a dual USB type A cable to get enough current for hungry HDD.

 

For next revision we will increase current limit on one of the port to address external HDD which requires more than the standard 900mA.

On the link @Igor sent, the spike is almost 2s long. My power meter has a 0.1s resolution so I don't know why it couldn't catch it… anyways I could plug my oscilloscope on the power meter to have a better resolution.

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