[ntp:questions] NetBSD GPS/PPS using 4.2.6p3

David Lord snews at lordynet.org
Tue Aug 23 17:57:18 UTC 2011


A C wrote:
> Hi everyone,
> 
> I read through most of the archives on various discussions on PPS from a 
> GPS and tried the suggestions listed there but none have seemed to work 
> in my case.
> 
> I am using a Globalsat ET212 GPS SiRF III based receiver module which 
> was originally used in cellular phone station equipment.  It is 
> configured to emit only $GPRMC at 4800 baud.  It has a PPS output 
> connected to DCD.
> 
> The system is a Sun IPX running NetBSD compiled with PPS_SYNC enabled. 
> The receiver is attached to /dev/ttyb with symlinks of /dev/gps1, 
> /dev/pps1, and /dev/gpspps1.  I downloaded the code for 4.2.6p3.  I've 
> used the program pps-api.c in the util directory of the ntp tarball to 
> verify that DCD is working.  The results show that the kernel PPS is 
> available:
> 
> # ../util/pps-api /dev/gps1
> 0.000000000 0.000000000 0 0 0.000000000
> 1313869152.080535506 0.000000000 1 0 -1313869152.080535412
> 1313869152.080535506 1313869152.960557409 1 1 0.880021903
> 1313869153.040540311 1313869152.960557409 2 1 -0.079982902
> 1313869153.040540311 1313869153.920562214 2 2 0.880021903
> 1313869154.000540116 1313869153.920562214 3 2 -0.079977902
> 1313869154.000540116 1313869154.880552020 3 3 0.880011904
> 1313869154.960541921 1313869154.880552020 4 3 -0.079989901
> 1313869154.960541921 1313869155.840593822 4 4 0.880051901
> 1313869155.920541727 1313869155.840593822 5 4 -0.079947905
> 1313869155.920541727 1313869156.800565630 5 5 0.880023903
> 1313869156.880537532 1313869156.800565630 6 5 -0.079971902
> 
> However, ntpd itself doesn't seem to be using the kernel code even 
> though the NMEA refclock driver is configured for it (at least I hope 
> it's configured):
> 

I've only just noticed this.
Not by default.

On i386 NetBSD-5.1 my kernel conf has amongst other changes
# options PPS_SYNC
options  PPS_SYNC


However I don't know if it applies to your architecture.


David




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