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ArduCAM / ArduCAM_USB_Camera_Shield

This is the repository for ArduCAM USB Camera Shield
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Multiple usb2.0 shield on one usb hub does not work #90

Open GoGoStudio opened 5 years ago

GoGoStudio commented 5 years ago

I attached two 2nd gen usb2.0 shield on on usb3 hub. I can only get pictures from one camera. Both work only if I attach them to usb root bus directly.

I tested 1280x960 mono @ 20hz. There are enough bandwidth at the usb3 hub. I think there might be a bug in the usb driver.

This does not work: /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M     | Port 2: Dev 7, If 0, Class=Hub, Driver=hub/4p, 480M         **| Port 3: Dev 24, If 0, Class=Vendor Specific Class, Driver=, 480M         |__ Port 4: Dev 25, If 0, Class=Vendor Specific Class, Driver=, 480M**

This works: /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M     |__ Port 7: Dev 39, If 0, Class=Vendor Specific Class, Driver=, 480M     |__ Port 8: Dev 40, If 0, Class=Vendor Specific Class, Driver=, 480M

ArduCAM commented 5 years ago

please note that the USB2 only use the HS port on USB3, the SS port is not used. So two USB2 camera shield will share the HS port on USB3.0 which is only 480Mbps. That's why it doesn't work as expect, because it doesn't use the SS port on USB3.0 at all. In this case you have to use seperate USB root hub or use USB3.0 camera shield, and it can get 50fps with each USB3.0 camera shield+AR0134. Let me know if you need more help.