Yo Udo! On Sun, 12 Aug 2018 11:05:20 +0200 Udo van den Heuvel <udo...@xs4all.nl> wrote:
> On 11-08-18 23:03, Gary E. Miller via devel wrote:
> > I've never found a good list of which products are FTS. I think the
> > LEA-M8F, LEA-M8T and NEO-M8T are FTS. Likely a few others, but not
> > the basic NEO-M8L, M, N, Q or S variants.
>
> Interesting info!
> Also: how could we interface these clocks to x86* hardware in the
> best way?
Theoretical best way that has never happened anywhere yet?
Or best practical way in current use?
gpsd knows about the NEO-M8T, but currently the results are no better
than with the NEO-M8N.
The key new feature in the TIMEMARK driver is haing the Linux kernel
output a signal back to the NEO-M8T so that the GPS can commpute the
CPU interrupt latency. This requires an FTS device. Then the new
ntpd/ublox driver uses that number to currect the timestamp sent to the
CPU.
This was on ARM. To do the same on x96, or amd64, would not be a big
deal. If you are handy at modifying kernel drivers. Instead of
toggling a RasPi GPIO pin as Lucas does, toggle a serial port line.
But all theoretical until we get a copy of Lucas's kernel mods and
ntpd driver.
RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
g...@rellim.com Tel:+1 541 382 8588
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