pleriche
Posts: 90
Joined: Mon Oct 14, 2013 8:44 am

/dev/video0 missing

Thu May 26, 2016 1:50 pm

I have a webcam working fine using motion on a fairly old Pi running a version of Jessie on which I may not have done an apt-get update, upgrade recently, but trying to get it to work on another is defeating me. Both use directly connected Pi camera modules (not USB webcams). The difference seems to be that the latter hasn't got /dev/video0 created.

Both have bcm2835_v412 in /etc/modules but lsmod only shows it loaded in the one which works. In the other (the updated one), modprobe -a bcm2835_v412 reports WARNING: Module bcm2835_v412 not found.

Suggestions please? Regards - Philip

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: /dev/video0 missing

Thu May 26, 2016 1:52 pm

Have you used raspi-config to "Enable camera"?

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: /dev/video0 missing

Thu May 26, 2016 3:00 pm

/etc/modules only gives a list of modules to try to load. If the camera isn't enabled (Phil's suggestion), or can't be detected, bcm2835_v4l2 will fail to load and log a message to dmesg.

Check if the camera can be detected using "vcgencmd get-camera", or if you can use raspistill to run the camera from userspace before trying to debug V4L2.
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pleriche
Posts: 90
Joined: Mon Oct 14, 2013 8:44 am

Re: /dev/video0 missing

Fri May 27, 2016 12:04 pm

PhilE: Err, yes. The camera had already been working fine with raspistill.

dmesg | grep bcm2835 gave no relevant messages.

But what idiot of a typographer ever thought it'd be a good idea to make a sans lower case L look so much like a figure one?

Changed bcm2835_v412 (vee four one two) in /etc/modules to bcm2835_v4l2 (four el two) and it now works. Thanks for the hint 6by9!

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