USB Ports for webcams

[jamdalla]

Hello,

We've been having an unexpected issue with the SBC4 detecting webcams. We plugged in a webcam via USB and initially could not get it to display video in the PhidgetSBC web interface, nor could we access the stream directly via VLC Player (in both cases accessing via a separate computer on network). After trying several avenues (rebooting, port forwarding, codec updates, etc.), we decided to simply plug it into a different USB port on the SBC4. That solved the problem! The camera did not work when plugged into the USB port nearest the Ethernet port. It then worked when plugged into the HDMI-adjacent USB port, and then again in the middle USB port. Back to the Ethernet-side port, it still does not work.

This doesn't seem to be just one defective port, as we've reproduced the issue with a second SBC4 and with 2 different webcam models (Phidgets and Logitech). On the second SBC4, the middle port only seemed to work after we had plugged the webcam into the HDMI-side port once and viewed the stream, not before. The Ethernet-adjacent port still does not work for the webcam, even after that.

All the USB ports work for other devices (e.g. RFID reader), and they do detect that the camera is connected (under Status > USB). They just don't allow us to view the webcam in the case of the Ethernet-adjacent ports.

Does anyone know why this happens? Is this the expected behaviour for all SBC4 units, and are there any other such known device/port incompatibilities?

Thanks!

Jamie

[mparadis]

The port nearest to the ethernet port is a USB On-the-Go port, while the other two are ordinary High-speed USB ports. Some webcams and USB Hubs have poor compatibility with USB On-the-Go, so it's recommended that you use one of the normal ports for these purposes.

[jamdalla]

Thank you for the quick reply!