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Issue of the code

Open yulan0215 opened this issue 3 years ago • 2 comments

Hi:

I used the code for my Ublox M8T, in the script: ublox_capture_raw.py. I saw the dev.configure_solution_rate(rate_ms=1000) part, you set it to be 1000ms. I found that if I set this parameter lower(For example 300), my NMEA messages would have some problems.

Is it possible for you to have a brief explain about this parameter? I will appreciate if you can give me some advices.

yulan0215 avatar Jan 04 '22 15:01 yulan0215

You can see from here https://github.com/tridge/pyUblox/blob/9e1df0ace2b141bd2a11c9a7bff7166e074df7b5/ublox.py#L357 that it is setting both the ubx navRate and measRate parameters.

  • measRate is the number of milliseconds between times that GPS measurements are taken.
  • navRate is the number of "cycles" that a position solution is calculated.

Halving measRate while keeping navRate constant means doubling the position calculation workload. If you lower the measRate too far, your hardware might not be able to keep up.

monkeypants avatar Jan 08 '22 14:01 monkeypants

You can see from here

https://github.com/tridge/pyUblox/blob/9e1df0ace2b141bd2a11c9a7bff7166e074df7b5/ublox.py#L357

that it is setting both the ubx navRate and measRate parameters.

  • measRate is the number of milliseconds between times that GPS measurements are taken.
  • navRate is the number of "cycles" that a position solution is calculated.

Halving measRate while keeping navRate constant means doubling the position calculation workload. If you lower the measRate too far, your hardware might not be able to keep up.

Thanks for your quick reply! Do you think this parameter will influence NEMA message or not? When I set this value below 1000ms my the timestamp of my sensor will have problem, the timestamp of this sensor is from ublox(NMEA + PPS).

I will appreciate if you can give me some ideas. Thx

yulan0215 avatar Jan 08 '22 21:01 yulan0215