[gpsd-users] BeagleBone Black and ST22 GPS module

[Mike]

Hello All

I'll open with thanks to the devs for a sweet piece of software! Most if 
not all of my issues in getting this going have been elsewhere....

The hardware obvious from the subject.

BeagleBone Black  rev. A6A if memory serves.
A ST22 GPS module found on ebay.  The chip is a Skytraq forget the 
version right off hand.
www.perthold.de has the datasheet for this module.

Originally I was going the China route with some flavor of Ublox6 
module.  Their newyears was on and I really didn't want to wait that 
long to receive a module.  Surfing blindly one night I found the ST22 
and it shipped from the US so I went for it.

Being neither a software or hardware person it's been a bit of a 
learning curve to get the UARTS working and getting the PPS signal seen.

Currently I'm running Debian testing (Jessie) with a kernel from Robert 
Nelson's git.

Linux arm-ticktock 3.8.13-bone40.1 #1 SMP Thu Feb 20 21:12:57 EST 2014 
armv7l GNU/Linux
Ntp is 1:4.2.6.p5+dfsg- straight from the Debian repositories.

It would seem that the gpsd shipped with either stable or testing, is 
either too old or not built with PPS support.  Perhaps someone can 
confirm this?  I've had to build gpsd: 3.10 (revision 3.10) in order for 
gpsmon to show PPS input.

Having to build the software isn't that big of a deal, I'm just lazy and 
would rather use a package and not have to bear the manual maintenance 
myself if it can be avoided.

Much of the info used to get this going was pulled from the gpsd website 
specifically  this page.

http://www.catb.org/gpsd/gpsd-time-service-howto.html

If there is any interest I may write more about my adventures in getting 
this up and running.

My main interest in posting was the PPS question.  Even if not answered 
perhaps it will help someone in the future with a similar situation.

The other point, with the hardware I've used < 75.00 USD shipped for a 
stratum 1 timeserver.  Color me a happy geek, the wife still just thinks 
I'm nuts....

address@hidden:~# ntpq -pn
     remote           refid      st t when poll reach   delay offset  
jitter
==============================================================================
+127.127.28.0    .GPS.                      0 l       4   32  377 
0.000    5.263   8.905
*127.127.28.1    .PPS.                        0 l       3   32 377    
0.000   -0.002   0.001
-199.104.120.74  43.77.130.254     2 u   23   64  377   68.425 2.065   5.921
-204.2.134.162   204.123.2.72        2 u   57   64  337  100.788 7.653   
4.365
+64.246.132.14   .CDMA.                 1 u     7   64  377 50.906    
0.025  30.099
-198.199.100.18  198.60.22.240    2 u   56   64  377   93.003 5.771   2.733
address@hidden:~#

28.0 still could use a bit a tweaking, its fudge factor is somewhere 
around +0.190 right now.
28.0 has no fudge adjustment and looks awesome to me.

Mike