GPS Time Stamping

Question on the APM saving GPS location: will that work on the Ardupilot or just the PX4?


Hi All,

Question about the GPS time stamping - will it work on the APM 2.5 or only on the PX4? Can’t tell based on the updates for the 2.75 release.



Hi Jimmy,
All boards will record GPS timestamps in the logs, and in camera capture log entries.
The only part that is PX4/Pixhawk specific is showing the dates on the logs when you list available log files. That is because those dates are the file dates on the FAT filesystem on the SD card, and the APM2 doesn’t have a FAT formatted SD card.
What would be nice is for MissionPlanner to look inside logs you download from an APM2 and get the timestamps from the GPS messages in the log, then rename (or set the date) on the downloaded logs so the user can see the timestamps more easily.
Cheers, Tridge

[quote=“jtprouty”]Question on the APM saving GPS location: will that work on the Ardupilot or just the PX4?

If you mean the rally points, then that works identically on APM1/APM2/PX4 and Pixhawk.
The same is true of the GPS coordinates in camera log entries (so you know the time and position of images taken with camera triggering.
Is that what you were referring to?
Cheers, Tridge

What format are the new time stamps in? I just looked in my CAM logs expecting to see some new time entries, and I’m still see what looks like the old epoch stamps.

Hi Iskess,
The time format is as two field, the GPS week and milliseconds since the start of the week. The GCS will need to convert that to a UTC time when it processes the logs (I’m hoping MP will do that soon).
I used that format as it is the natural format for the uBlox GPS, and gives us maximum precision without doing 64 bit maths.
Cheers, Tridge

Has anyone noticed when downloading onboard data logs (.log.gpx) what used to be full of gps data is now an empty log? or is it just my pram setup. This log was very useful for me due to a timestamp matched with lat long.