C++ smartdashboard bandwidth paper?

Technical C/C++
1

We are having trouble with auto mode and the smartdashboard on the field.

There are rumors of a white paper describing this problem and what to do. I am not able to find that paper.

Looking for some help?

Our autonoumous works fine in the pit with full practice mode. On the field when we at alone it works fine (thank to the fta for his help). With other bots on the field the autonomous fails to work. The robot is enabled bit does not run.

Any ideas?

2

This may be the paper that was referred to.

Here’s a link to the 2013 Field management system whitepaper. http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2013/FMSWhitePaper_RevA.pdf

There’s discussion there about bandwidth limits, and the corresponding video resolution and compression settings.

If you were attempting to send high-bandwidth camera data back to the smart dashboard for video processing in autonomous, it’s possible your bandwidth limit could be surpassed; what happens after that limit gets hit is harder to predict.

Good luck!

3

If you’re running on win7, you can use Resource Monitor to get a quick picture of network utilization

  1. Close other consumers of bandwidth (e.g., browser)
  2. Start -> type Resource Monitor
  3. Click on the network tab
  4. Pane at upper right shows network utilization

You can also use Performance Monitor to see more than the last 60 seconds:

  1. Same as above
  2. Start-> type Performance Monitor
  3. Click on the Performance Monitor in the tree view
  4. At the bottom of the pane, delete the “% Processor Time” entry as you don’t care about that value
  5. Click the plus button
  6. Scroll to ‘Network Interface’ and expand it
  7. Select ‘Bytes Total/sec’
  8. In the “instances of selected object” list, select the network interface that the robot is connected to
  9. Click Add, then OK.

You’ll see a plot of network utilization.

Other hints:

If you’re using C++, ensure you have the March WPILib update.
Only write items you need for competition to the SmartDashboard.
Comment out any printf statements.
Lower the resolution and frame rate of the camera per the instructions on http://wpilib.screenstepslive.com/s/3120/m/8559/l/89729-configuring-an-axis-camera.