USB Microscope

English Hardware
#1

I just got a MicroView USB Digitial Microscope, but it doesn’t work on Leap 15.1. It works on my Lenovo Android tablet, and on an old Windows XP laptop, so I know it’s not defective. I could just use the tablet, but what fun is that? Running “Cheese”, it says “no device found”.

I ran this:

lsusb
Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 002: ID 0a5c:21e8 Broadcom Corp. BCM20702A0 Bluetooth 4.0
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
**Bus 003 Device 013: ID 0ac8:3420 Z-Star Microelectronics Corp. Venus USB2.0 Camera**
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 002: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 9570:0301  
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

I assume the bold line is the microscope.

#2

Hi
That’s your problem, it’s from Venus :wink:

If you run the command usb-devices instead, can you post the relevant lines related to the device.

Also if you open a terminal and switch to root user, unplug the device and run the command udevadm monitor and then plug the device in and post the relevant output.

#3 
usb-devices

T:  Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 15 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0ac8 ProdID=3420 Rev=01.00
S:  Manufacturer=Vimicro Corp.
S:  Product=Venus USB2.0 Camera
C:  #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=128mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=0e(video) Sub=01 Prot=00 Driver=uvcvideo
I:  If#= 1 Alt= 0 #EPs= 0 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo

udevadm monitor
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[10776.557241] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1 (usb)
KERNEL[10776.559097] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0 (usb)
KERNEL[10776.561521] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/video4linux/video0 (video4linux)
KERNEL[10776.561612] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/input/input25 (input)
KERNEL[10776.561900] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/input/input25/event12 (input)
KERNEL[10776.561980] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.1 (usb)
UDEV  [10776.596483] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1 (usb)
UDEV  [10776.598169] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0 (usb)
UDEV  [10776.598820] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.1 (usb)
UDEV  [10776.600953] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/input/input25 (input)
UDEV  [10776.605202] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/video4linux/video0 (video4linux)
UDEV  [10776.657653] add      /devices/pci0000:00/0000:00:12.2/usb3/3-1/3-1:1.0/input/input25/event12 (input)
#4

Hi
That all looks good, do you have another app you can try eg mpv, vlc etc?

#5

Install luvcview or guvcview and test it with that packages.

#6

Tried vlc

Your input can't be opened:
VLC is unable to open the MRL 'v4l2:///dev/video0'. Check the log for details.

Where is the log found?

#7

I tried guvcview, it says “No video device found”
Also tried luvcview, got this:

luvcview
luvcview version 0.2.1 
Video driver: x11
A window manager is available
video /dev/video0 
ERROR opening V4L interface 
: No such file or directory
#8

I installed v4l-conf, v4l-tools and v4l-utils. Then I ran this:

v4l-conf
v4l-conf: using X11 display :0
dga: version 2.0
WARNING: No DGA direct video mode for this display.
mode: 1920x1080, depth=24, bpp=32, bpl=7680, base=unknown
/dev/video0 [v4l2]: no overlay support
#9 
webcam
reading config file: /home/user/.webcamrc
[codecinfo] Error: Cannot open plugin directory /usr/lib64/libquicktime (forgot make install?)
v4l2: open /dev/video0: No such file or directory
vid-open: failed: libv4l
no grabber device available
#10

In Yast, “libquicktime0” was installed, and there was also “libquicktime” that wasn’t, so I installed it. Now I don’t get the complaint about it, but still no luck

webcam
reading config file: /home/user/.webcamrc
v4l2: open /dev/video0: No such file or directory
vid-open: failed: libv4l
no grabber device available
#11

I don’t see “.webcamrc” in my home directory. The closest thing is “.wxcam”.

#12 
v4l2-ctl --all
Failed to open /dev/video0: No such file or directory
#13

Sorry, forgot to plug microscope in!

v4l2-ctl --all
Failed to open /dev/video0: Device or resource busy

Why would it be busy?

#14

What are the permissions of the /dev/video0 entry?

ls -l /dev/video0

Second question: is your user member of the video group ?

#15 
ls -l /dev/video0
crw-rw----+ 1 root video 81, 0 Mar 11 19:42 /dev/video0

I just added my user member to the video group and logged out & back in, but Cheese and guvcview still don’t see any device.

#16

I tried this

ls -l /dev/video0
crw-rw----+ 1 root video 81, 0 Mar 11 19:52 /dev/video0
user@localhost:~> ls -l /dev/video0

After trying Cheese, I got this


ls: cannot access '/dev/video0': No such file or directory
user@localhost:~> ls -l /dev/video0

If I unplug the microscope and plug it in again, I get this

ls -l /dev/video0
crw-rw----+ 1 root video 81, 0 Mar 11 19:52 /dev/video0
user@localhost:~> ls -l /dev/video0
#17

Sorry about those code things, I pasted the wrong parts, should be:

I tried this


ls -l /dev/video0
crw-rw----+ 1 root video 81, 0 Mar 11 19:52 /dev/video0

After trying Cheese, I got this


ls -l /dev/video0
ls: cannot access '/dev/video0': No such file or directory

If I unplug the microscope and plug it in again, I get this

ls -l /dev/video0
crw-rw----+ 1 root video 81, 0 Mar 11 19:52 /dev/video0
#18

You need to reboot for that, IIRC

#19

I tried rebooting, still no luck. I did see something odd, though. If I start Cheese, then I unplug the microscope and plug it back in, while Cheese is still running, in the preferences it then shows the microscope, greyed-out. It still won’t work though.

#20

Run cheese from a terminal window, repeat that and look at the messages in the terminal window.