LitePlacer.com forums

I'll probably buy a Liteplacer soon, and I've been fervently browsing the existing documentation. One of the upgrades I might do after building it is replacing the cameras for USB3-capable ones, and I was wondering if any of you are using any.

Other than the USB3-interface, the other specs for the camera, like resolution or FPS, can stay similar to the old specs. That's because my motivation for the camera upgrade has nothing to do with resolution or framerate. The reason I'm considering a camera upgrade is 1) to reduce the number of cables going to the computer and 2) to reduce the PC host requirements. Needing separate host controllers for the two cameras is a PITA, and I also don't like the idea of occupying 3 USB ports, not to mention 3 cables from machine to PC. Ideally I would place a USB hub at the machine and lay a single USB cable to the PC. But due to how USB hubs work, even if the connection between the hub and the PC is USB3, the total (and shared) bandwidth at the hub's upstream port available for USB2 downstream devices will still only be USB2 (480Mbps). With other words, USB hubs don't upgrade USB2-traffic to USB3 at their upstream port. But if the cameras were USB3 to begin with, then I could just place a small USB3-capable hub, and solve problems (# of cables machine<->PC, USB bandwidth for 2 cameras, and the need for multiple host controllers) all at once.

Personally, I don't see the need for USB3 capable cameras. Whether using the LitePlacer software or OpenPnP, computer vision is only done on stationary images. FPS is not really important. Concerning USB ports - I don't know what kind of system you're running, but any sort of desktop machine will work. The processing needs are not much, and it's easy to add an additional USB card if needed. Also, unless the cameras are on separate ports the cameras will not be properly enumerated by the LitePlacer software and will not be able to differentiate them (at least that has been my experience).

> …the cameras will not be properly enumerated by the LitePlacer software…

I’d like to get details when this happens. Although the cameras are the same and have the same id string, the software uses an unique device identifying code. Sometimes it is a bit quirky to set up, but I haven’t seen a case where it is unsolvable. But of course, there are a myriad of systems, hubs and configurations; if you are willing to help on your side, I’d be happy to sort this out with you.