Hello, I am trying to use four webcams connected to a USB hub which is connected to the AGX. The hub has its own power supply. However, all the webcams do not work at the same time and the behaviour is odd.
I’ve tried both USB C ports and the USB A port. The problem is if I try to view each webcam on its own they work, but once I try to view more than 2 simultaneously the other 2 webcams are no longer detected with ls* -ltrh / dev / video . Some times lsusb -t lists all the webcams even though they cannot be used.
Another odd behaviour is that after I try to access all four webcams and fail, if I reboot the AGX no USB be devices are detected, unless I unplug the hub and reconnect my mouse.
While shutting down/rebooting I notice output similar to this:
usb device descriptor read 64 error
and while booting:
usb device not responding to set address
I really don’t get how sometimes it would connect and let me see them one at a time but after rebooting all devices stop working.
How can I fix this? Thank you.
The usb bus shares the same bandwidth. Thus, we need to know your webcam resolution and format first.
Will the hub work if other devices (non-webcam) are in use?
Hello, I’ve tried the hub on a normal PC (to see if the problem was the USB hub and not the AGX) and I got the same issues, after trying to access the multiple webcams and it fails to detect them the hub sometimes refuses to work even with a USB keyboard or mouse.
And sometimes after a few minutes (like 5) the mouse or keyboard may connect but the PC or AGX no longer finds any webcam connected to it.
Another weird behavior is when unplugging and plugging back in the hub, on both my PC and the AGX, the display turns off for half a second when the ground of the USB hub touches the ground of the USB host.
Also, it is a USB 2.0 hub. The webcams are all Full HD 1080p so the bandwidth was probably maxed out.
This hub seems unsuitable for my purpose therefore I need to know what can I purchase, to allow me to use four webcams with the Jetson AGX, that is guaranteed to work? A USB 3.0 hub? A PCIe USB hub? Other technologies I don’t know about? You suggestions would be most helpful. Thank you @WayneWWW .
What is the usecase you want to achieve? How many webcams do you need?
Also, do you also see the monitor goes off when you plug current usb hub to the AGX xavier? What kind of monitor are you using now? DP on typeC port or the HDMI one?
Our custom carrier had an issue where high speed devices connected to the onboard USB hub would continuously reset if another high speed device was plugged into one of the other ports on the jetson, but if you plugged in the devices to the hub first, it was fine. We fixed it by adding usbcore.autosuspend=-1 to the kernel command line options in /boot/extlinux/extlinux.conf.
Give that a try and see if it helps.
That bug took me forever to figure out.
Hello, We need to use four webcams at the same time. This is used for human detection on four locations. All webcams are USB 2.0.
The monitor issue happens on both the AGX and my PC, when plugging in, when the hub’s outer conductor touches the conductor on the AGX or PC. The displays are both HDMI, but this is not a big issue at the moment.
I shall try this and get back to you.
IT made it more stable, thanks for the suggestion. Any ideas of suitable hubs?