HOWTO: scons gpsd build incorrect and ntpshmmon gives no data

Gary E. Miller gem at
Thu Aug 9 02:33:43 UTC 2018


On Thu, 9 Aug 2018 02:15:51 +0000 (UTC)
MIKE MAJOR via devel <devel at> wrote:

> >> In the HOWTO section "Live-test the GPS", the reader is instructed
> >> to build gpsd using: $scons timeservice=yes magic_hat=yes
> >> nmea0183=yes fixed_port_speed=9600 fixed_stop_bits=1  
> > Not really.  That is just an eplanation for what clockmaker --build
> > does.  
> I guess that is where I misunderstood. I'm used to a HOWTO explaining
> the steps to perform a certain task. The steps are laid out in order.
> The reader then follows along, repeating the steps on his/her
> computer to achieve the task. 

As the howto says:

"Most of the remaining instructions do not have to be done by hand.  You can
download link:clockmaker[clockmaker], a Python script which
does much of this recipe for you."

I'll admit many people have the same misunderstanding as you...

> It was not clear to me that the expectation is to use clockmaker to
> perform the tasks and read along only for instructional purposes.

How can we make it clearly than the text just quoted from the document?

> I
> thought I could choose to do one of two things: take the easy way and
> run clockmaker to save some typing OR take the detailed way and type
> the commands one by one. 

Yes, but like antyhing else done two ways, they have diverged a bit.

People have been workong on the text for the last week.  Suggestions

> > Not good.  Is your GPS really on /dev/gpsd0?  Is your GPS running
> > NMEA?  
> I see my mistake now. I read the first 2 lines below to be the same
> when they are not: # ./gpsd/gpsmon /dev/gpsd0
> # ./gpsd/gpsd /dev/gpsd0 
> # ./gpsd/ntpshmmon

Also not an uncommon mistake.  Any way that ccould be made more clear?

> Everything is working correctly now. 

Except the document...

> >> Cross checking with the clockmaker script showed that 2 options
> >> are>> missing from the HOWTO text: ublox=yes mtk3301=yes  
> > Not really.  The script is for NMEA mode.  To keep things simple.  
> clockmaker has this:      scons timeservice=yes magic_hat=yes
> nmea0183=yes ublox=yes mtk3301=yes fixed_port_speed=9600
> fixed_stop_bits=1 The HOWTO has this:   scons timeservice=yes
> magic_hat=yes nmea0183=yes fixed_port_speed=9600 fixed_stop_bits=1 I
> was pointing out that the two don't match. In my subsequent testing,
> clockmaker produced a correctly working gpsmon, where the HOWTO text
> did not. 

Eric will have to fix that.  Anything else divergent?

I'd make both the script and the doc compile all the drivers.  Missing
drivers has been a continuing source of problems.  But not up to me.

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at  Tel:+1 541 382 8588

	    Veritas liberabit vos. -- Quid est veritas?
    "If you can’t measure it, you can’t improve it." - Lord Kelvin
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