Re: [gpsd-users] Missing fixes

[Gary E. Miller]

Yo Deven!

On Tue, 20 Feb 2018 12:09:28 -0800
Deven Hickingbotham <address@hidden> wrote:

> I'll send the raw data directly to you.  10hz and 4hz.

Please, list only.  I'm not the only one here, there are a lot of interested
lukers.

> I tested at 4hz and there were no missing fixes.

As expected.

Do the math.  115200 is about 10k chars a second.  At 10 Hz that
is 1k chars each cycle.  But the GSVs alone can be more than 1k!  So
one GSV group and you already lost the game.

> Maybe I could further optimize the message stream from the GPS?

Maybe.  And/or up the rate to 230400.

> If I just needed time, lon/lat, speed & track, could I just enable
> the RMC sentence and turn everything else off?

You could try it.  Might be enough.

> If I wanted to add altitude, looks like I would have to add the GGA 
> sentence.

Or, better to go u-blox binary.

> And in order to get epx and epy, would I have to add both GSA & GSV?

Or, better to go u-blox binary.

And do you really need 10Hz?  What can possibly happen at 10Hz?  Even
the msall mass of a small drone can't change direction, much, at that
rate.

Most autopilots are averaging to remove the jitter, not trying to add
more jitter.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin

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