So tried to convert DAT to a csv file, but no luck in getting the csv to upload to the phantom log viewer or healtydrones
Help !
The DAT file is here.
Dropbox - FLY135.DAT
I didn't see this until just now. I'm not sure how you converted to .csv. I loaded the .DAT into CsvView which then converts the .DAT to a .csv and then visualizes that .csv. CsvView can be obtained by going
here.
My analysis of this incident is not all that informative. I'll do some speculation to make up for that
Shown are the values for Yaw and magYaw. Yaw is the Flight Controller's notion of the AC heading. Yaw is derived mostly from the IMU values. Yaw is the value you see in the form of a red triangle presented by the DJI Go App. magYaw is a diagnostic computed by DatCon which CsvView uses to convert the .DAT. Unlike Yaw, magYaw is computed from the current value of the magnetometers.
At time 68.1867 the values of Yaw and magYaw separate, the FC declares a YAW_ERROR_LARGE and presents that as a "compass error" in the Go App. The problem is that the separation is not very large. In addition, there is no apparent cause for the separation. Two points should be emphasized. magYaw is a diagnostic computed by DatCon. At best it's a proxy for some calculations done by the P3. Secondly, there are many variables that DatCon doesn't know about.
I'm not a DJI engineer writing the code for the P3 FC so the following is just speculation on my part. The FC can't always be correct and has to always be looking for indications of possible problems. In particular, if it's possible the heading is incorrect then it doesn't want to use that heading to navigate. But, it's impossible for any algorithm to detect an incorrect heading with 100% accuracy. You have to choose - err on the side of not detecting a problem, or err on the side of false positives.
I get the impression that, with every FW update, the trend is toward more false positives and less undetected heading errors. Personally, I think this is the right trend. I've adopted the perspective that an
occasional mid-flight "compass error" is the P3 saying "I'm confused, can you fly this thing in ATTI mode until I get it figured out". Not that there is a serious issue that needs fixing.
There is an exception. If the Go App is saying "compass error" then
DON'T initiate an RTH. The P3 is telling you that it's not sure about it's heading value. If you initiate an RTH it will use whatever that heading value is to navigate back home - probably in the wrong direction.