Add Camera check node

[iory]

What is this

camera_check node monitor the camera device and its topic.
User can watch the status by diagnostics.

Following picture is the example use case of xtion.

[furushchev]

It is indeed a nice feature!

I just wonder if the method checkUSBExist works for checking the connectivity to any camera? (Did you check with other cameras?)
If it works with enough many devices, I think it should also be proposed to upstream.

[iory]

Thank you for your review!

I just wonder if the method checkUSBExist works for checking the connectivity to any camera? (Did you check with other cameras?)

For USB camera, we can see the device in /dev/*.
In this implementation, we can specify the device_path by rosparam.
When this param is set, we simply check whether the device_path exists.
https://github.com/jsk-ros-pkg/jsk_common/pull/1595/files#diff-b6c4b4c056574236a2a1660b146ba70cR55
When device_path is not set, we can check the connection of USB by vendor_id and product_id .
https://github.com/jsk-ros-pkg/jsk_common/pull/1595/files#diff-b6c4b4c056574236a2a1660b146ba70cR61
Users can easyly know this value by lsusb command.

 ~  lsusb
Bus 002 Device 003: ID 8086:0b07 Intel Corp.
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 138a:0097 Validity Sensors, Inc.
Bus 001 Device 002: ID 5986:111c Acer, Inc
Bus 001 Device 004: ID 8087:0a2b Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

8086:0b07 means vendor_id:product_id

[k-okada]

please update
https://github.com/jsk-ros-pkg/jsk_robot/blob/master/jsk_pr2_robot/jsk_pr2_startup/jsk_pr2_sensors/check_openni_node.py
to use this new node to see if the image is available, the cehck_openni_node.py also checks case when the image is published, tbut he data is not validate.
I hope this new camera-check node can find this situation too.

[k-okada]

@iroy still waiting for your comment on #1595 (comment),
did you also point out launch files that use this feature