Realsense working on Surface Pro 3 but not on gaming laptops

[Philip_N_]

Hi all,

On the surface pro 3 i5 4300U the f200 install fine, appears in device manager and all data sources can be accessed. On two laptops (i7 3820 + i7 4790 both with intel usb 3.0) the realsense installs and color streams can be accessed but as soon as depth is called the camera disconnects and remains unresponsive. It appears like it is trying to draw too much power from the USB port. Has anyone had any experience using a powered external USB3.0 hub to provide the current needed to start the lasers? I have tried using an Icron Optical USB extender but that does not work with the f200 and I discovered that it will only transmit USB3.0 data, and I thought I have read somewhere that there is a USB2.0 component to the f200? The extender works fine with a Kinect v2, however. 

Any help would be greatly appreciated.

Thanks,

Phil

[MartyG]

Hi Philip,

Intel's specs for the RealSense camera say that it will not work with USB hubs and needs to be connected directly to a USB 3 port on the computer.

The RealSense camera can perform the basic functions of an ordinary USB 2.0-level webcam (e.g video feeds in Skype) but for its higher functions it needs the power of a USB 3 port.

Your theory that the camera may be drawing too much from your laptop ports may be accurate.  When I tried adding a USB 3 expansion card to a desktop PC, it was necessary to attach an additional 5 volt power cable from the power supply to a connector on the expansion card to provide more power to the ports on the card (as the card on its own did not draw enough from the computer to power high-drain USB 3 devices), and even then it wasn't enough.  In the end I upgraded to a new 2014-built motherboard with USB 3 ports built in and that ended my USB problems.

In other words, there seemed to be disagreement between manufacturers about how much power should be provided to USB 3, with some USB 3 expansion card makers not even offering the option to connect a power cable to provide the additional 5V. 

I think the main reason why the Kinect 2 worked with your extender whilst RealSense did not is that Intel purposely set high specs for RealSense to help future-proof it and enable more powerful applications to be created for it.  They decided not to support old legacy tech like pre 4th Generation Intel CPUs and versions of Windows prior to 8.1 so that RealSense would not be held back.

[Philip_N_]

Hi Marty, thanks for the reply. It is good to know that someone has had similar experiences with under powered USB ports.

I'm not sure I entirely agree with the future-proofing by setting high specs. No one wants to devote a large proportion of computer resources just to do computer/machine vision work, and if they want to put this in mobile or IoT devices then they need to ensure that no matter how good the depth data is, the battery doesn't runs out after 20 minutes.

I will try and start splicing some cables or make a breaker box to supply 5V to the camera and report back on any success.

Thanks,

Phil

[MartyG]

Yeah, the RealSense App Challenge launched in Sept 2014 but hardly anyone on this forum really started getting anywhere with creating their entries until around November because we were all trying to persuade the camera to work with the equipment we already owned.  In the end, once it became clear that legacy tech was an absolute no-no, a lot of people who didn't have a recent computer ended up upgrading their machine or buying a new one in order to be able to enter the contest.

It all turned out fine in the end, but those first weeks where we tried to put together hardware and software setups that the camera was happy with were difficult times.  We sure learned a lot about how RealSense hardware works though!

[Philip_N_]

I completely understand this, it is still a developer kit after all. I'm hesitant to call a 2 year old gtx680 powered laptop and a 2 week old gtx980 powered laptop legacy, but I get your point and know that USB3 compatibility is hit and miss everywhere.

I just don't think it has been officially mentioned anywhere that the power output of a USB3.0 port could be an issue, even if it is attached to an Intel USB3.0 chipset with a 4th gen CPU. Perhaps someone from Intel or Creative could comment on this? If it is as simple as providing a steady 5V with sufficient current then it would be good to get an official recommendation from Intel on external hubs/breaker boards etc. I'm getting one delivered on Thursday and will report back with any news. Has anyone else managed to get it working through a 'powered' external USB3.0 hub?

Thanks,

Phil