NI releasing/designing new controller for FRC

[Tom Line]

Originally Posted by Greg McKaskle

I have two years logs for 1718. Their typical usage for matches in 2013 St Louis was under 30%. At earlier 2013 competitions it is several points lower, and in 2012 at the end of the season it was 40%. I don't have logs for the other teams on my laptop.

To add information to this:

In 2012 the two biggest chunks of processor usage were our vision processing and our speed control on the shooter. The vision processing would increase CPU utilization 100% but only for a fraction of a second before we started shooting.

Our speed control ran in a timed loop and that was the single biggest contributor to our CPU usage that year. We scaled it back from 5 ms to 10 or 15 (I can't remember the final one) to improve CPU utlization.

In 2013, our speed control loop was the biggest user again. We didn't use vision at all. During the year, we stopped using the old '09 classmate because the lag was noticeably worse than using a new laptop with an I5 processor, even with the stock driverstation.

I wouldn't say that CPU usage has ever limited what we've done in competition. Teams need to understand how the changes they make affect CPU usage though. Perhaps it's time to flash a message in the diagnostic window that cpu usage is approaching 100%. That will at least let users know when something is wrong. Many new users don't know enough to look at the charting tab.

There is no getting around it though: an FRC control system is not simple. Personally, I don't think that it's too complicated for high school students to utilize.


The single biggest issue I have with the cRIO and other systems is compile time. In order to completely remove compile time issues from our robot, we now have every single constant or modifiable value stored in text files. Updating something is a matter of changing the text in the file and uploading to to the cRIO via FTP. It takes about 5 seconds after power on, since you don't have to wait for code init or anything else. The cRIO operating system boots very quickly. The change was necessitated by the time in 2011 at Worlds when we weren't able to finish tweaking our two tube auton because it was taking too long to compile. We can do it while the robot is live, too, and a single button press reloads all the constants from the text files.

The only time this year we actually reprogrammed anything was when we added a drive-to-mid-line and stop on the center discs in case we played against 469. On another note, this is the second time we specfically had to write an auto mode to try to stop them - the first time was in 2010.