Re: Garmin GLO2 with GPSD

[Gary E. Miller]

Yo Fred!

On Thu, 30 Sep 2021 15:53:11 -0400
"Fred Hillhouse" <fmhillhouse@comcast.net> wrote:

> >Even for free, maybe not worth it.  It has no documentation, except
> >how to setup the Bluetooth.  Nothing on protocols, accuracy,
> >configuration, etc.  
> 
> Garmin is typically tight lipped on their stuff. For what I am doing,
> it puts on the correct spot. NMEA is the only output.

It likely can do Garmin Binary or Garmin Text as well.

> >I have heard reports you can get NMEA out the USB port.  
> 
> Can't prove that by me and I am not lost working with GPS receivers
> in general. I did see one report of a 'maybe' on this list but no
> confirmation. Besides, sharing one USB GPS to several users is not
> really possible without a lot of work.

Prolly not hard.  That is what gpsd does.

> >> I am attempting use with a Raspberry Pi Zero W but I suspect it
> >> would be similar to all RPi with WiFi/Bluetooth.  
> 
> >Yes, nothing special about the Pi.  It works (almost) like any other
> >Linux host.  
> 
> Ah, there is the rub. While I am use to using tools on my Win PC, I
> am a total noob with Linux. I suspect I need something to
> differentiate between the 4 different channels. I suspect there may
> be similarities for the Dual Corp. X160GPS receiver (also supports 4
> users).

Lost me.  How do you have 4 channels?  I thought you had one GPS sending
you one Bluetooth stream.  And that was working fine for you.

> >> On the RPiZero, I have it running enough such that cgps -s will
> >> give me position and other data. The Status never changes.  
> 
> >That means the data path from the device, to gpsd, to cgps is fine.
> >No need to look at the path more, it works.  
> 
> Yes, but which channel? And, are the multiple channels confusing the
> issue?

Lost me.  What do you mean by "channels"?  You have one GPS gicing ou
one set of fixes.  Do you have 4 GPS sending you 4 streams?

> >Never heard of Direwolf.  
> 
> Amateur radio application that can operate on multiple platforms.
> 
> Dire Wolf is a software "soundcard" AX.25 packet modem/TNC and APRS
> encoder/decoder. It can be used stand-alone to observe APRS traffic,
> as a tracker, digipeater, APRStt gateway, or Internet Gateway
> (IGate). For more information, look in:
> https://github.com/wb2osz/direwolf/blob/dev/doc/README.md

Yeah, I have heard of APRS stuff using GPS.  But way outside of what
I have seen.

> Direwolf acquires data from GPSD. It never see a valid position. My
> suspicion is that the connection between rfcomm and GPSD is not
> complete.

My guess is a simple gpsd version mistamatch.  You can not mix and match
gpsd client and server versions.  Have their dev contact me and I
can help them debug it.

> The is one reason for the Raspberry Pi. It is my Linux educational
> tool and I have things I want to accomplish with it.

I love the Pi.

> >>  Status:     3D FIX (0 secs)  
> 
> >You said you never got status?  But there it is.  You have a 3D fix,
> >and you just got it (not old).  
> 
> The GPS has been running for over 2 days in a good location with
> excellent sky view. Yes, the satellites could be in places that makes
> it less than perfect but I have a solid 3D fix and have ad that all
> along.

So, again, what is the problem?

> >So, what is the problem again?  You cgps looks fine to me.  
> 
> Other than the 3D Fix is not even 1 second old in cgps,

Ah, that is a good thing.  Old fixes are not good, a fresh new fix is good.
If you want old fixes, turn off your GPS.

> I don't know.
> That does smack of something, I just can't identify it. My only guess
> is something between the Bluetooth sub system (?) and GPSD is not
> connected correctly.

If you are getting very fresh and current updates, that can not possibly
be a connection issue.

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

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

pgpcma5H2MNec.pgp
Description: OpenPGP digital signature