Re: COEX GPS (model UBX-M8030 IC) on Raspberry Pi 4 Model B 2018 connection issues

[Mike Simpson]

Systemd(oing too much) seems to grab port 2947 on Raspbian and I haven’t worked 
out the necessary incantation to stop it doing so. 

> On 22 Jul 2021, at 21:20, Gary E. Miller <gem@rellim.com> wrote:
> 
> Yo Aranza!
> 
>> On Thu, 22 Jul 2021 15:00:24 -0700
>> Aranza Shaccid Leon <leon18@pnw.edu> wrote:
>> 
>> I used udev rules in order to connect my GPS when I had it on a
>> separate USB connection (had to disconnect from the flight controller
>> for this to work though) and in the rules, I named it ttyGPS.
> 
> That standard symlink name is "/dev/gps0".  Yours works, just adds
> a bit of confusion.
> 
>> The gpsdebuginfo above is with the gpsd socket/gpsd disabled and with
>> the GPS plugged into only the flight controller.
> 
> Which, of course, is not the configuration you could not get to work
> and raised an issue about.
> 
>> This is the gpsdebuginfo with the gpsd socket/gpsd enabled (is this
>> what you mean be get gpsd running?)
> 
> No.  I have always, firmly, railed aginst enabling gpsd under
> systemd(umb).  Which is why you were instructed to turn it off, and did
> in fact urn it off.
> 
> 
>> and the GPS plugged into only the USB.
> 
> I take that to mean NOT also plugged into the flight controller, so
> once again NOT the configuration you want and that we were trying to debug?
> 
>> /usr/bin/lsof
>> + lsof -iTCP:2947 -s TCP:LISTEN
>> COMMAND PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
>> systemd   1 root   70u  IPv6  16942    0t0  TCP localhost:gpsd (LISTEN)
>> systemd   1 root   75u  IPv4  16944    0t0  TCP localhost:gpsd (LISTEN)
>> gpsd    735 gpsd    4u  IPv6  16942    0t0  TCP localhost:gpsd (LISTEN)
>> gpsd    735 gpsd    5u  IPv4  16944    0t0  TCP localhost:gpsd (LISTEN)
> 
> That is very odd.  Somehow systemd(roll) and gpsd both have port 2947 open?
> Which is why I don't do systemd(umber).
> 
>> + lsof -c gpsd
>> + sed -nE 1p;/CHR|LISTEN/p
>> COMMAND    PID USER   FD   TYPE     DEVICE SIZE/OFF  NODE NAME
>> gpsd       735 gpsd    0u   CHR        1,3    0t0     5 /dev/null
>> gpsd       735 gpsd    1u   CHR        1,3    0t0     5 /dev/null
>> gpsd       735 gpsd    2u   CHR        1,3    0t0     5 /dev/null
>> gpsd       735 gpsd    4u  IPv6      16942    0t0   TCP localhost:gpsd 
>> (LISTEN)
>> gpsd       735 gpsd    5u  IPv4      16944    0t0   TCP localhost:gpsd 
>> (LISTEN)
>> gpsdebugi 1005 root    0u   CHR      136,0    0t0     3 /dev/pts/0
> 
> Notice that gpsd is NOT conencted to your GPS.  Your systemd(umber)
> config is broken.  But I can't help you there since I do not do
> systemd(umbest).
> 
>> + ps ax
>> + sed -nE 1p;/gpsd/p
>>  PID TTY      STAT   TIME COMMAND
>>  735 ?        S<s    0:00 /usr/sbin/gpsd /dev/ttyGPS
> 
> You tried to get it to open /dev/ttyGPS, but it failed.  See above.
> 
> Since you used a non-standard name, the debug output is less helpful.
> 
>> Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
>> Bus 001 Device 003: ID 26ac:0012
> 
> You still did not answer my question on what 26ac:0012 is, it is
> not obeying the USB standard...
> 
>> Bus 001 Device 004: ID 1546:01a8 U-Blox AG [u-blox 8]
> 
> At least the u-blox is plugged in.
> 
> But I can't help you when systemd(umpkopf) is controlling gpsd.
> 
> 
> 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