allamm wrote:
I thought you can't attach multiple cameras to a hub, am i right? If i can, what are the recomended hubs for iPi.
http://www.everythingusb.com/usb2/faq.htmhttp://en.wikipedia.org/wiki/Universal_Serial_BusAt 640x480 in raw Bayer mode, you can attach up to two Sony PS Eye cameras to a hub. But in that case you should be careful not to attach two hubs to the same USB controller.
USB controller is not the same as USB port. Ports are dumb electrical contacts. USB controller is an intelligent device that sits deep inside your PC. Modern PCs (both Intel-based and AMD-based) have two USB 2.0 controllers integrated into motherboard. PC manufacturers don't make any markings to help identify ports connected to the same controller. You should experiment with different ports to find out the best configuration. Usually, closely placed ports (like this:
http://en.wikipedia.org/wiki/File:USB_Front_Port.jpg ) connect to the same controller (so you should avoid plugging all four cameras to such pair of ports via hubs), while ports on different sides of laptop tend to connect to different controllers (so you should plug two cameras to left side and two cameras to right side).
Make sure you use USB 2.0 hub (not USB 1.0). There exists a gazillion different USB hub models, most of them should be good. It is hard to recommend any particular hub. The only thing I can say about hubs is: expensive hubs does not seem to be any better then cheap hubs.
At 320x240, you probably can attach all four cameras to the same hub and still get good frame rate.