[time-nuts] NEO-M8N vs. NEO-M8T
Gary E. Miller
gem at rellim.com
Mon May 21 14:19:47 EDT 2018
Yo Scott!
On Mon, 21 May 2018 13:08:06 -0500
Scott Newell <newell+timenuts at n5tnl.com> wrote:
> >The NEO-M8T is an FTS product.
>
> Are you sure about that? I thought the M8T was timing, and the M8F
> was FTS. Please check your firmware version string against the table
> on page 8.
I stand corrected. I do see UBX-TIM-TP:
Class: TIM(0xd) ID: TP(0x1), len: 0x10
tow:1519310.000000000 qErr:-0.000000048400 ps, week:2002
flags:0xa refInfo:0x0
is GPS, UTC available
Which says the next PPS is going to be -48.4 nano seconds out. Similar
to the 52 nano seconds quantization error of a RasPi 3B.
Here is another one, -101 nano seconds out:
Class: TIM(0xd) ID: TP(0x1), len: 0x10
tow:1522360.000000000 qErr:-0.000000101900 ps, week:2002
flags:0xa refInfo:0x0
is GPS, UTC available
That is more than double my quantizaation error!
Now, how to I tell the Linux kernel to apply that correction?
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem at rellim.com 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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