Trying to figure out why we are experiencing an error when trying to do Drivetrain Characterization with SysID. The error is below, we get this each time we try to load our data in the analyzer:
The provided JSON was invalid! You may need to rerun the logger. Error message:[json.exception.type_error.302] type must be number, but is null
Looking at the data I don’t see anything obvious that is null where there should be a number, but of course, there’s tons of data points, and any attempt to view the data becomes an overwhelming mess. I’ve included the deploy configuration we used as well as some of the logger data that is not working, We didn’t mess with the quasistatic ramp rate or dynamic step voltage, because we thought we had plenty of room to run.
Does anyone see anything that we have done wrong here? I can’t wrap my head around what we could have missed, as we’ve basically just been sitting here following along with the docs site.
As an update, I used NotePad++ when I had more time to fiddle with this and found a single null in each file for the left velocity value during a fast test, and I have no idea why.
“Fixing” the null by replacing it with the same value as the other side’s velocity value causes some of the data to actually load. But I get the error “Kv must be greater than zero” and the graphs are incomplete.
I suspect this is because I have my config set up wrong (left data is negative, right data is positive). I’ll fix it and test again on Tuesday when I’m in our build space and have enough room to complete a test.
We’re working on telemetry changes to make the logging more robust next year. There are a number of intermittent bugs that have nothing to do with user error - try re-running your test routine if this happens.