Start multiple camera nodes from single roslaunch XML

[nmertins]

System Configuration

Version	Known Good	Your Configuration
Operating System	ubuntu 14.04	ubuntu 14.04
Kernel Version	4.4.0-13	4.4.0-040400-generic
R200 FW	1.0.72.06	1.0.72.06
librealsense	0.9.1	0.9.1

It'd be nice to be able to start up multiple camera nodes from a single .launch file. For example:

<launch>
    <include file="$(find realsense_camera)/launch/realsense_r200_rgbd.launch">
        <arg name="camera"      value="rs1" />
        <arg name="serial_no"   value="1234567890" />
    </include>

    <include file="$(find realsense_camera)/launch/realsense_r200_rgbd.launch">
        <arg name="camera"      value="rs2" />
        <arg name="serial_no"   value="0987654321" />
    </include>
</launch>

Running the script above results in the following error which brings down the process:

[ERROR] [1460047172.302085622]: RealSense Camera - Error calling rs_create_context ( api_version:4 ): 
UVCIOC_CTRL_QUERY:UVC_SET_CUR error 5, Input/output error

[mdhorn]

Official support for Multiple cameras is being release soon.
Launching multiple camera from a single launch file wasn't in our original acceptable criteria, but we've capture this and it will get addressed -- may not be in the first release.

[prarobo]

@mdhorn Do you have a timeline for this release?

[mdhorn]

We don't have a hard date for this fix. It is high on the list, but there are a couple of other items that are in front of it.

The issue stems from librealsense assuming all cameras would be started from the same process/thread whereas our ROS module launches each as a separate process via a nodelet.

[reaganlo]

@nmertins @prarobo This required some changes at the librealsense level, which has been implemented in their latest "master" branch IntelRealSense/librealsense@bff3ab5

We are waiting for librealsense to make a "release", to update our ROS repo with the related launch file changes. In the mean time, you could do the following:

• Download the latest librealsense "master" branch as mentioned above.
• Copy the file "realsense_r200_multiple_cameras.launch.xml" in the attachment into the "launch/includes" folder.
• Copy the file "realsense_r200_multiple_cameras.launch" in the attachment into the "launch" folder. Make sure to read the comments in the file and make the changes accordingly. Then launch the file.

multiple_cameras.zip

Thank you for your patience and please let us know if this works.

[mdhorn]

Fixed in Release 1.1.0