Jump to content
  • 0

Checking for undervoltage/undercurrent on the Rock64's USB3 port?


va88
 Share

Question

Armbianmonitor:

Hey guys,

 

I heard that the USB3 port of the Rock64 outputs up to 950mA.

 

I have this external HD (WD My Passport), one of those 2,5'' external HDDs that are powered solely by the USB3 port. From what I've gathered, this should need no more than 650mA.

But it doesn't work on the Rock64.

After mounting the thing, if I try to write and read, it just disconnects with a bunch of dmesg errors. It makes a little click sound after the spinning builds up. Looks like there's not enough energy (it works fine on my desktop).

 

How can I check and monitor the voltage and current delivered by the USB3.0 on the Rock64? 

My power supply is kind of generic, even though it says 5V 3A. 

The rpi shows a lightning icon right, but the Rock64 doesn't, so I can't be sure the power supply is at fault.

 

Edited by va88
Link to comment
Share on other sites

14 answers to this question

Recommended Posts

  • 0

Try using a usb voltage meter on the USB3 port of your Rock64 and see what voltage it is.
With undervoltage you've got problems with mechanical hard drives.
 

Link to comment
Share on other sites

When discussing a problem make sure to provide full logs!

  • 0
14 hours ago, va88 said:

My power supply is kind of generic, even though it says 5V 3A

Do you power it via the Barrel Jack?

You can measure the voltage on the GPIO pins or if you have with an USB-Voltmeter just search on eBay

Link to comment
Share on other sites

  • 0
2 hours ago, NicoD said:

Try using a usb voltage meter on the USB3 port of your Rock64 and see what voltage it is.
With undervoltage you've got problems with mechanical hard drives.
 

 

I don't have one of those. I'll see if I can get my hands on one.

 

 

1 hour ago, Tido said:

Do you power it via the Barrel Jack?

You can measure the voltage on the GPIO pins or if you have with an USB-Voltmeter just search on eBay

 

Yes, it's powered with a 3,5mm barrel jack. Unfortunately I don't have a multimeter nor a USB-voltmeter. 

I'll try to buy these tools.

Link to comment
Share on other sites

  • 0
40 minutes ago, Tido said:

multimeter

You can buy multimeters very cheap. I've bought my most used one for $4(euro) at Action. I've compared it with my more expensive one. Almost no difference.
The same with USB voltage meters. Very cheap, and very handy to have.

Link to comment
Share on other sites

  • 0
3 hours ago, Tido said:

Maybe you know someone who has one ;)

 

3 hours ago, NicoD said:

You can buy multimeters very cheap. I've bought my most used one for $4(euro) at Action. I've compared it with my more expensive one. Almost no difference.
The same with USB voltage meters. Very cheap, and very handy to have.

 

Yeah, I just ordered one from ebay. I should make some tests soon.

 

By the way, how to test undervoltage in a situation like this? Do I point the sticks at the USB port while the HDD is in use?

Link to comment
Share on other sites

  • 0
13 hours ago, va88 said:

 

 

Yeah, I just ordered one from ebay. I should make some tests soon.

 

By the way, how to test undervoltage in a situation like this? Do I point the sticks at the USB port while the HDD is in use?

Best was to buy a USB volt meter. Plug it into the used USB port, and plug your hard drive into the (data) port of the voltmeter. Then you'll see the powerdraw + the voltage.


With a multimeter you can only check voltage. Do not put the leads into the USB ports. You can short them like that if you do it wrong. Best way to check voltage with a mutlimeter is by measuring the 5V pin and GRND pin on the gpio's when the hard drive is connected, and also when disconnected to see the difference. Again, watch out you don't short it. You may not let the leads touch each other when they're onto the GPIO's.

More into on this in this thread. The same problem, just another connector. There's tons of threads about this. Or check here to visually see this happening with another board.

 

Link to comment
Share on other sites

  • 0
8 hours ago, NicoD said:

Best was to buy a USB volt meter. Plug it into the used USB port, and plug your hard drive into the (data) port of the voltmeter. Then you'll see the powerdraw + the voltage.


With a multimeter you can only check voltage. Do not put the leads into the USB ports. You can short them like that if you do it wrong. Best way to check voltage with a mutlimeter is by measuring the 5V pin and GRND pin on the gpio's when the hard drive is connected, and also when disconnected to see the difference. Again, watch out you don't short it. You may not let the leads touch each other when they're onto the GPIO's.

More into on this in this thread. The same problem, just another connector. There's tons of threads about this. Or check here to visually see this happening with another board.



 

 

A USB meter would be nice. Do I need to have a 3.0 USB meter to test a USB 3.0 port? The regular ones are quite cheap.

Link to comment
Share on other sites

  • 0
47 minutes ago, va88 said:

A USB meter would be nice. Do I need to have a 3.0 USB meter to test a USB 3.0 port? The regular ones are quite cheap. 

To be future proof USB 3.0 is better. But all mine are USB2.
Transfer rates are a lot higher with USB3, so I expect it to  consume a bit more.
Dit you try it on the USB2 ports of the Rock64? Did you try other storage devices on the Rock64? Do they mount ok?
I should have a 2.5" drive laying around and I've got a usb3 to sata adapter. If I find time I'll try it out. Can't promise anything.

Link to comment
Share on other sites

  • 0
1 hour ago, NicoD said:

To be future proof USB 3.0 is better. But all mine are USB2.
Transfer rates are a lot higher with USB3, so I expect it to  consume a bit more.
Dit you try it on the USB2 ports of the Rock64? Did you try other storage devices on the Rock64? Do they mount ok?
I should have a 2.5" drive laying around and I've got a usb3 to sata adapter. If I find time I'll try it out. Can't promise anything.

 

Yes, I tried another external hdd. My USB 3.0 external HDD will mount on the USB 3, but will disconnect with load. It won't mount in the USB 2 port.

 

My USB 2.0 external HDD will not work properly on the USB 2.0 port, but works in the USB 3.0 port (I'm using it now).

Link to comment
Share on other sites

  • 0
8 hours ago, NicoD said:

Transfer rates are a lot higher with USB3, so I expect it to  consume a bit more.

The USB specification defines how much power a device is allowed to consume. So back in the days, some USB-HDD came with 2 USB-A cable (500mA per port), to feed the hungry device on USB 'only'.

With USB 3 this was increased to 900mA iirc - it is written in the internet or in one of TKs posts, ahh wait, he deleted everything here. So you must look it up in the net.

Link to comment
Share on other sites

  • 0
4 hours ago, Tido said:

The USB specification defines how much power a device is allowed to consume. So back in the days, some USB-HDD came with 2 USB-A cable (500mA per port), to feed the hungry device on USB 'only'.

With USB 3 this was increased to 900mA iirc - it is written in the internet or in one of TKs posts, ahh wait, he deleted everything here. So you must look it up in the net.

 

From what I've heard, this USB 3.0 drive I have (650mA) consumes less than the 2.0 drive I'm using now (850mA). Developers say that the Rock64 outputs up to 950mA on the USB 3.0 port. Should be enough, so that's why I'm trying to test the power supply.

 

 

Link to comment
Share on other sites

  • 0
On 5/28/2019 at 10:47 AM, NicoD said:

With a multimeter you can only check voltage. Do not put the leads into the USB ports. You can short them like that if you do it wrong. Best way to check voltage with a mutlimeter is by measuring the 5V pin and GRND pin on the gpio's when the hard drive is connected, and also when disconnected to see the difference. Again, watch out you don't short it. You may not let the leads touch each other when they're onto the GPIO's.

 

I just did this test and saw that the voltage is below 5V (around 4,4 and 4,6) when the Rock64 is using a USB2.0 HDD connected to its USB3.0 port (the only method that works until now, with bad write performance).

Also, there's oscillation to under 4V, even if there's a small load.

If the power supply were good we should see steady 5V or more, right?

 

Can anyone point me to a legit power supply in Aliexpress? Or maybe some seller on ebay that ships to South America?

Link to comment
Share on other sites

  • 0
1 hour ago, va88 said:

 

I just did this test and saw that the voltage is below 5V (around 4,4 and 4,6) when the Rock64 is using a USB2.0 HDD connected to its USB3.0 port (the only method that works until now, with bad write performance).

Also, there's oscillation to under 4V, even if there's a small load.

If the power supply were good we should see steady 5V or more, right?

 

Can anyone point me to a legit power supply in Aliexpress? Or maybe some seller on ebay that ships to South America?

That indeed isn't good at all. I'm from Europe so I haven't got a clue where to buy when you're from South-America.
It's this PSU.
https://www.cloudmedia.com/?product=rock64-pinebook-pine-h64-5v-3a-switching-power-supply

I'm using a different one for it, a 4A EU PSU. But 3A should be sufficient. 

This is what you need to look for : 5V (at least) 3A Type H 3.5mm OD/1.35mm ID barrel ‘coaxial’ type

I'd trow away that PSU you've got before it damages anything(hd/sd-card). I've seen a lot of undervolting in my times :) but under 4V is very rare.

With a good PSU/cable you should never go under 4.8V. (tell that to the raspberry pi foundation) :)
Good luck, greetings.

 

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
 Share

×
×
  • Create New...