[time-nuts] Fury ntp refclock

[Scott Mace]

I've created a ntpd refclock driver for the Fury GPS receiver.
The refclock is based on the NMEA driver.

http://www.intt.net/time-nuts/ntp-fury.diff

The driver was created because the Fury does not fully
implement the ptime:tcode? T2 string.  The output is
not on-time and the status fields are always 0.  So,
it is not going to work with the hpgps refclock.
As it turns out the T2 string is rather limiting anyways.

Fortunately, the Fury supports a partial NMEA mode, where
it will emit on-time $GPGGA sentences.  The driver then
probes the Fury for other statistics using the GPS? SYNC?
DIAG? and MEAS? commands.  Also the driver will check
for leap second warnings.  The stats are concisely output
to clockstats.  Some logic for handling holdover thresholds
and to detect if the Fury is unlocked has been added.

flag3 logs the stats, flag4 logs the gpgga sentences

output from Fury OEM SMA connector version w/ LPRO-101
54654 13857.011 127.127.45.0 68 1 0 0 2.65e-12 2.10e-09 44.50 1.992863 0.000004 10.53 7 7 1 41 -1
54654 13867.010 127.127.45.0 68 1 0 0 2.67e-12 2.20e-09 44.50 1.993594 0.000004 10.53 7 7 1 41 10
54654 13877.011 127.127.45.0 68 1 0 0 2.99e-12 2.20e-09 44.50 1.993680 0.000004 10.53 7 7 1 41 -13
54654 13887.013 127.127.45.0 68 1 0 0 2.83e-12 2.10e-09 44.50 1.993442 0.000004 10.53 7 7 1 41 -4


lifetime ppslock holdduration holdover fee tint temp efc ocxocurrent ocxovolt sat_vis sat_track pulsestat pulseacc pulsesaw



sample ntp.conf:



server 127.127.45.0 prefer minpoll 4 maxpoll 4
fudge 127.127.45.0 time1 0.012 #115200
#fudge 127.127.45.0 time1 0.024 #57600
fudge 127.127.45.0 flag3 1
#fudge 127.127.45.0 flag4 1

server 127.127.22.0 minpoll 4 maxpoll 4

tos mindist 0.010

statsdir /var/log/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable




	Scott