Re: [gpsd-users] OT: Radio Module Time

[Gary E. Miller]

Yo George!

On Thu, 4 Aug 2016 10:52:52 -0600
George Sexton <address@hidden> wrote:

> This is a little off-topic, but there's a lot of overlap between the 
> issues I'm having and GPSD, so I thought I'd ask here.

You might also ask the NTPsec folks: 
    https://lists.ntpsec.org/mailman/listinfo/

A guy over there wrote his oen SHM() driver for a CPG PCIe card.  Your
project not to dis-similar.

> After fixing the WWVB support (doing the pull request is my next 
> project), I tried to get it to work in PPS mode. I've found that the 
> driver PPS support only works in serial port mode, not GPIO mode for
> a raspberry pi :(

Ouch.  But the code to pull kernel PPS time stamps out ofa GPIO pin
is not large.  You might be able to copy it out of gppsd.

> I've thought about looking at the SHM code for GPSD and seeing if I 
> could get some ideas on how to handle it.

It is easy to put time in SHM().  That is a common approach for
uncommon receivers.

> and it was pretty easy to get going. The only issue I had was to get
> the PPS lock, I had to put in a time offset for the NMEA sentences.

If that worked, what's the problem?

> made one stab at getting the NTPD .20 driver to work, but it's
> expecting NMEA and PPS to come out of the source so that's not going.

Refclock 22 should be a lot easier.  

> I suppose one option would be to fake a GPRMC sentence and output it.

Easier to get SHM to work.

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

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