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Stereo Pi V2 with Ubuntu Mate 20.04

Posted: Mon Jan 10, 2022 10:32 am
by karlfra
Hi Guys

I started a project with the Stereo Pi v2 and an Pi CM4.
I use Ubuntu Mate 20.04 64bit, because of ROS.

I have at the moment a problem that the cam1 is not detected.

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vcgencmd get_camera 
gives me:

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supported =2, detected = 1
the missing is the cam1 connection.

I just added change the config like this:

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# The following settings are "defaults" expected to be overridden by the
# included configuration. The only reason they are included is, again, to
# support old firmwares which don't understand the "include" command.



include syscfg.txt
include usercfg.txt
Did i forget something to change in the config or is there another problem?
Hopefully you can help me with this problem.

Re: Stereo Pi V2 with Ubuntu Mate 20.04

Posted: Tue Jan 11, 2022 7:45 am
by karlfra
So i have managed now to detect 2 cameras.

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mmal service 16.1 (platform:bcm2835-v4l2):
I deleted some dtoverlays from the startup and now its seems to work.

I can use both cameras on after another, but not simultaneously.
Is there an easy way to check the two cameras if they work simultaneously.

Re: Stereo Pi V2 with Ubuntu Mate 20.04

Posted: Thu Jan 13, 2022 7:46 am
by Realizator
Hello karlfra,

You need to choose the subsystem you are planning to use with the cameras. As you may know, RPF did dramatic changes in the video subsystem (announced here first, and more details later here.)

To say briefly, you can either use the old mmal-based approach (using older kernel and firmware, AND our specific device-tree/dt-blob), or the new libcamera way. In the second case you should not use our device tree but use the camera-specific overlay (take a look at this answer of 6by9 on RPF forum).

AFAIK you can use libcamera to access both cameras but from the independent processes only. Cite: "A single camera device shall be usable by a single process at a time" from the libcamera docs. Since libcamera has no native stereoscopic support (yet), you can access both cameras independently and, to get an ideal sync, use the hardware synchronization (using oscillators paralleling or the sensors' XVS sync).