About logging LPS TWR data

[easy98]

Hi,

I am currently setting up the LPS system based on #108 using the TWR mode. My purpose is to get the LPS raw data, which seems to be the distance between the tag and anchors here. I would like to directly log it in this line.
But I am not sure if it's the right way to log that data and if it's possible to to that? Also,I noticed that my position estimation is not so correct based on here. If this state estimation is predicted according to this estimator_kalmen?

Thanks in advance.

[whoenig]

If you want to log the data in real-time over the radio, this is the correct approach. All you need to do is figuring out the logging variable of interest - in your case ranging.distance0 etc. If you just want to look at the data in post-processing, I recommend using the uSD-card deck instead (you will be able to log more variables at a higher rate compared to the over-the-radio mode).

If you use the LPS, the Kalman filter is always active automatically, so you should be getting the state as predicted by the on-board filter.

[easy98]

It works! Thanks Whoenig！

[easy98]

Hi,

When I switched the mode to TDOA3 on the python client, I changed the logging variable to "tdoa3.tdoa". But when I run "roslaunch crazyswarm hover_swarm.launch", It throws an error saying “Could not find tdoa3.tdoa in log toc!”. Then I rechanged the logging variable to "ranging.distance0", no error occurred but the value of "ranging.distance0" was always zero and the mode was actually TDOA3 rather than TWR. I am not sure why I have this error.