Address cameras by serial number and support running multiple concurr…

[liz-murphy]

…ent processes

Addresses #7

[liz-murphy]

I see a lot of this error and often only one process starts up successfully:

[ERROR] [1457594957.962800200]: RealSense Camera - Error calling rs_create_context ( api_version:4 ):
UVCIOC_CTRL_QUERY:UVC_SET_CUR error 5, Input/output error

[reaganlo]

@liz-murphy The pull request is giving compilation errors; so I am not able to test it. Could you please look into it.

[reaganlo]

@liz-murphy
I am assuming that you are getting the "UVCIOC_CTRL_QUERY:UVC_SET_CUR error 5" while using multiple cameras. Our current code does not support multiple cameras. We have this requirement in our backlog. So with multiple cameras, you may come across errors like "UVCIOC_CTRL_QUERY:UVC_SET_CUR error 2" and "UVCIOC_CTRL_QUERY:UVC_SET_CUR error 5". Even the librealsense examples (cpp-capture) would give the similar errors with multiple cameras connected.

But you should not be getting this error with a single camera. If yes, I would suggest running the librealsense example (cpp-capture). If you get the same error with the librealsense example too, then it could be either:

• The camera firmware is not updated. The latest stable firmware version is 1.0.72.06. To update the firmware you will need to download and run this executable on a windows machine with the camera connected to a USB 3.0 port. OR
• The uvc driver patches were not applied correctly. Refer to the README for installation steps.

Hope this helps.

[liz-murphy]

@reaganlo should compile for you now.

I have the right firmware and everything is patched. If I modify cpp-capture to open individual devices I am able to repeatedly and stably have 2 cameras streaming all frames on 1 machine.

This is the view from my desktop with 2 cpp-capture processes running concurrently:

Attached are the launch files for testing purposes. Note that the need to spawn multiple cameras in their own namespaces is a fairly ubiquitous in robotics.

realsense_qqvga.launch.txt
realsense_r200_nodelet.launch.xml.txt
realsense_r200_rgbd.launch.txt

[reaganlo]

@liz-murphy , FYI I have created an Issue for the enabling ros params at #11