tridge / pyUblox

python Ublox module
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Issue of the code #9

Open yulan0215 opened 2 years ago

yulan0215 commented 2 years ago

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.

monkeypants commented 2 years ago

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.

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.

yulan0215 commented 2 years ago

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