Contents
Camera1394 Problems
Camera Not Found
Error:
$ rosrun camera1394 camera1394_node _guid:=08001000821f2a [ INFO] [1277163420.502573259]: Found camera with GUID 8144361026320a0 [ INFO] [1277163420.536846060]: Found camera with GUID 800461000821fa2 [FATAL] [1277163420.537210073]: [camera] exception opening device: [Camera1394::open]: Could not find camera with guid 0800461000821f2a
Check:
- Is that the correct GUID? Note that in the example above it is not, the last two digits of 800461000821fa2 were mistyped.
Solution:
- Use the correct GUID. Or, if there is only one camera, omit the GUID so the driver will connect to the first available.
Check:
Is the non-responsive camera plugged in correctly with an IEEE 1394 cable of the correct type? Is the camera getting power, either from the 1394 cable or from some other source?
Solution:
- If not, correct the cabling.
Check:
Can coriander connect to the camera?
Solution:
If so, carefully note the parameters provided by the device. Start the camera1394 driver using the same parameter values. If not, the camera may be hung.
No Bus Access Permissions
Error:
Could not initialize dc1394_context.
Check:
Does /dev/video0 exist?
$ ls -l /dev/video* crw-rw----+ 1 root video 81, 0 Feb 1 20:20 /dev/video0
Does your user ID have access permission?$ id uid=1001(joq) gid=1001(joq) groups=44(video),115(admin),1001(joq)
Solution:
Grant your user ID access to group video.
No Images Shown
Error:
- Image blank or not changing.
Check:
$ rostopic hz camera/image_raw subscribed to [/camera/image_raw] average rate: 15.344 min: 0.049s max: 0.082s std dev: 0.01015s window: 14 average rate: 15.176 min: 0.049s max: 0.082s std dev: 0.00699s window: 29 average rate: 15.088 min: 0.049s max: 0.082s std dev: 0.00585s window: 44 average rate: 15.076Does the message rate summary (shown above) appear periodically?
Solution:
- If so, the driver is publishing data. Check that image users connect to the correct topic names.
Check:
Start the reconfigure_gui for this camera:
$ rosrun dynamic_reconfigure reconfigure_gui
Are the video_mode, frame_rate, and iso_speed parameters set as expected?
Solution:
- If not, set the correct parameter values in the GUI.
Check:
Can coriander display images from this camera using the same combination of parameters?
Can coriander display images from this camera using the some combination of parameters?
Solution:
If so, change the parameters to a combination that works. Otherwise, the camera is probably hung.
Camera Hung
Error:
- Many IIDC cameras are very sensitive to invalid combinations of parameters. The device firmware may lock up if commanded to do something impossible.
Check:
- Does the camera respond after resetting the 1394 bus?
# install package for Ubuntu or Debian distributions: $ sudo apt-get install libdc1394-utils $ dc1394_reset_bus
- Does the camera respond after its cable is disconnected and reconnected?
- Does the camera respond after the kernel drivers are unloaded and reloaded?
- Does the camera respond after the computer is rebooted?
Solution:
- If so, restart the driver.
Slow Frame Rate
Error:
Camera is not achieving the commanded frame_rate
Check:
$ rostopic hz camera/image_raw subscribed to [/camera/image_raw] average rate: 15.027 min: 0.054s max: 0.081s std dev: 0.00732s window: 15 average rate: 15.004 min: 0.026s max: 0.101s std dev: 0.01129s window: 30 average rate: 15.004 min: 0.026s max: 0.101s std dev: 0.01130s window: 45 average rate: 14.968 min: 0.026s max: 0.101s std dev: 0.01260s window: 60Is the driver publishing raw images at the expected rate?
Solution:
If not, start the reconfigure_gui for this camera:
$ rosrun dynamic_reconfigure reconfigure_gui
Some feature settings may be prevent the camera from meeting its desired frame_rate. For example, if the shutter time is longer than the time between frames, the camera will either fall behind or force the shutter time to a shorter exposure. In poor lighting conditions, it may be necessary to adjust several parameters to get an acceptable compromise between picture brightness and frame rate.