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USB - Details on electrical requirements

MerlinC
Protege
After recently upgrading my graphics card to GTX1080 (worked well with my GTX780 but with performance limitations) and not paying attention to what USB 3.0 port I used for the specific devices I had recurring sensor and HDMI failures. The only way to get around the issue I was able to find by trial and error is to plug the sensor to a USB 2.0 port.

Reading all the issues with regard to USB connection of the rift I assume that my USB 3.0 Ports are not able to provide the power/current required by the sensor and/or headset. According to the motherboard  manufacturer the USB ports are according to USB 3.0 standard.

Due to not having had any issue with other USB devices I assume that the current drawn by my rift is either n the edge or over the rated power for USB 3.0 ports. Was not able to find any information what maximum current is specified for the sensor and headset.

Could you please provide this information?
45 REPLIES 45

TwoHedWlf
Expert Trustee

MerlinC said:


stevieh said:

I had my Oculus replaced for black screen issue just received the new one today and have the same issue, gutted!

 
Why is it that difficult to provide the current drawn from the devices sensor/HMD? If they are in the limits specified by USB standard I do have something in my hands to get either back to my motherboard or USB card vendor.


If you're that hugely stressed over the current drawn by them, why don't you measure it?  Shouldn't take anything more than a short USB extension and a cheap multimeter, cut it open and measure the current through the +5v wire.

Should be red.

Hornet_F4C
Adventurer

TwoHedWlf said:
If you're that hugely stressed over the current drawn by them, why don't you measure it?  Shouldn't take anything more than a short USB extension and a cheap multimeter, cut it open and measure the current through the +5v wire.


This should work as well?

https://www.amazon.com/Centech-USB-Power-Meter/dp/B00DAR4ITE

Would be suprised if that wasn't already tested by somebody.

TickTock
Heroic Explorer
HMD + USB3 repeater reads 0.31-0.41A (bounced around).  Two sensors, a USB3 hub and a USB3 repeater read 0.61A. This is while in operation.
"I'm not crazy about reality, but it's still the only place to get a decent meal."
 -Groucho Marx

TickTock
Heroic Explorer
The active USB repeaters appear to be negligible. I get about the same reading at the HMD as when measured at the PC side of the repeater (bounces around so hard to say exactly).  Unable to check the sensors independently since the hub is mounted to the ceiling in a way that prevents reading the meter when it is plugged in.
"I'm not crazy about reality, but it's still the only place to get a decent meal."
 -Groucho Marx

Hornet_F4C
Adventurer

TickTock said:

HMD + USB3 repeater reads 0.31-0.41A (bounced around).  Two sensors, a USB3 hub and a USB3 repeater read 0.61A. This is while in operation.


That means around 0.9A for three sensors + 0.4A for the HMD.

Is the USB specication meant per port or per controller? If every port can deliver 0.9A each, this should be fine, but if the 0.9A are shared between all ports of the same controller that could be a problem for some setups...

stevieh
Honored Guest
You guys are way more technical than I am, good luck though I appreciate it shame Oculus aren't involved in coming up with a solution or ideas with you as the  community, maybe they will eh?

MerlinC
Protege



TickTock said:

HMD + USB3 repeater reads 0.31-0.41A (bounced around).  Two sensors, a USB3 hub and a USB3 repeater read 0.61A. This is while in operation.


That means around 0.9A for three sensors + 0.4A for the HMD.

Is the USB specication meant per port or per controller? If every port can deliver 0.9A each, this should be fine, but if the 0.9A are shared between all ports of the same controller that could be a problem for some setups...



USB specification is .9A per port and w/o specific modes like battery charging or power distribution. But to be sure you should have a look at the technical data provided by the vendor of your card or just ask him.

MerlinC
Protege







TwoHedWlf said:
If you're that hugely stressed over the current drawn by them, why don't you measure it?  Shouldn't take anything more than a short USB extension and a cheap multimeter, cut it open and measure the current through the +5v wire.


This should work as well?

https://www.amazon.com/Centech-USB-Power-Meter/dp/B00DAR4ITE

Would be suprised if that wasn't already tested by somebody.



You are both right.

Yes I will do the measurement on my rift and sensor although this values should be available at Oculus. Challenging thing is that the really interesting currents are those drawn when the sensor failure and/or blackouts occur. Thus the cheap multimeter most likely will not do the job to get a trace of the current for a view 500 ms before and after the event.

Hicks613
Heroic Explorer
Why did Oculus drop the AC adaptor?  This used to be an effective way to inject additional power to the HMD.

XlordB
Adventurer
I so want to get into this thread and find out what the maximum power draw a sensor or the rift would draw when its pushed.. if we can find out the maximum the rift or sensors draw then we can theoretically measure our maximum power per usb port and then figure out whether usb 2 OR 3 are actually no good for the rift and MAYBE it might be worth looking into a pci card with usb 3.1 ports instead of usb 3.

Im currently due to move house so im busy painting and stuff no time to look more into these pressing issues.

HEY cyber since your like the inside man for us can you get any info on the power specs of the rift or at least the sensors.?