GPS very slow to pick up sats #gps


Kk6qms
 

My DRAWS is working fine- but I have 2 issues.
1- GPS ant is in a window but is VERY slow to pick up. I just moved it outside with a 100% view of the southern sky incl unobstructed to east and west. Why does it take so long? Currently I rebooted and at over 26mins of boot time I STILL do not have a fix. My cell phone in same loc as antenna has 22 sats visible and a fix on 17 of them. This is NOT going to work for SOTA etc. No way I can wait this long for clock/loc/etc.
2- Had a  7"12V touch screen w connector right of the 12V leads powering the DRAWS- and it burned up a smd component and stopped working. Regulated switching PSU was a steady 13 or 14V.
Any input appreciated- 
Clifford - KK6QMS


Kk6qms
 

Anyone? Slow to non functional GPS?


 

Once the GPS is up and running, look at the command cgps or gpsmon and see how many satellites and their strength.  You may have a weak or defective antenna?

Have you put the battery on the DRAWS™ board?   It should give you warm boots for the GPS vs a cold boot.  The battery is really only designed to take over when power is removed and has a relatively short life.

A cold boot of the GPS can take several minutes, a warm boot will typically be less than a minute.

On Sat, Mar 27, 2021 at 11:34 AM Kk6qms <kk6qms@...> wrote:
Anyone? Slow to non functional GPS?



--


John D. Hays
Director

  


Basil Gunn
 

Anyone? Slow to non functional GPS?
What version of HAT do you have?

udrcver.sh


Kk6qms
 

I checked the battery- was .275V and luckily I had new ones on hand. Booting up now- pic attached for hat version (I don't know how else to check the version)
Thx


Kk6qms
 

I have another new identical antenna which I just put on and rebooted. Pulled satellites withing a few short minutes. Not sure if it was battery or 2nd antenna. Thank you for your help.


Basil Gunn
 

Glad you have things working.

I don't know how else to check the version
You can display the version by running script "udrcver.sh" that I
mentioned in previous post.

Kk6qms <kk6qms@arrl.net> writes:

I checked the battery- was .275V and luckily I had new ones on
hand. Booting up now- pic attached for hat version (I don't know how
else to check the version) Thx


Kk6qms
 

Both antennas work (one has much longer feed line than the other). I am wondering why there is no altitude data in CGPS and incorrect data in GPSMON (~800ft ASL- I am at 2500' ASL)


 

Are you sure it’s not 800m ?

73,
Bryan K7UDR
NW Digital Radio



On Mar 28, 2021, at 4:31 PM, Kk6qms <kk6qms@...> wrote:

Both antennas work (one has much longer feed line than the other). I am wondering why there is no altitude data in CGPS and incorrect data in GPSMON (~800ft ASL- I am at 2500' ASL)


Kk6qms
 

How do I run? I tried:
./ udrcver.sh
udrcver.sh
run udrcver.sh
cd to root then above
THANKS


Kk6qms
 

Yes- exact same antennas as was shipped w DRAWS- 3V-5V @ 1575.42MHz


Kk6qms
 

OHHHHHHH 800m as in ASL- yes that is 2600ft - I SEE- thx


Kk6qms
 

OK- so I tested both antennas more- and it is certain that the antenna with the long feed line does NOT work. W/O antenna I let DRAWS lose fix- upon connecting long lead ant- nada- but connecting the short lead antenna results in very fast fix and 9 used satellites.


 

How long is the redline?

73,
Bryan K7UDR
NW Digital Radio



On Mar 28, 2021, at 4:49 PM, Kk6qms <kk6qms@...> wrote:

OK- so I tested both antennas more- and it is certain that the antenna with the long feed line does NOT work. W/O antenna I let DRAWS lose fix- upon connecting long lead ant- nada- but connecting the short lead antenna results in very fast fix and 9 used satellites.


Kk6qms
 

ACK- sry for all the posts- but ultimately BOTH antennas are identical w feed lines of same length- but one works and one does not. If I could edit posts here I would have.

Thx


Kk6qms
 

OMG now neither antenna when reconnected gives any fix. I am flailing here unsure how the system is supposed to respond.


Kk6qms
 

I have used the DRAWS manager to stop the GPSD service- connect one of the 2 antennas (I marked them 1 and 2) and restart the GPSD service. Neither antenna gets a fix after 10mins.
I then shutdown the DRAWS station- connected each antenna- and waited 10mins. Neither obtains a fix in CGPS or GPSMON. 
I really do not understand why results are so unpredictable up to this point.


Basil Gunn
 

If you are using the NWDR19 image then the udrcver.sh script is in your local bin
directory /home/pi/bin

You can verify that by opening a console and type the following:

which udrcver.sh

If nothing is displayed then you are most likely not using the NWDR19
image.

Did you follow the "Getting Started Guide"?
https://nw-digital-radio.groups.io/g/udrc/wiki/8921

Also to run something in your current directory it would be ./udrcver.sh
with no space between the ./ and the program you want to execute. In
this case you do not need to do that since udrcver.sh should be in your
PATH.

https://unix.stackexchange.com/questions/397524/what-does-the-mean-dot-slash-in-linux

Kk6qms <kk6qms@arrl.net> writes:

How do I run? I tried:
./ udrcver.sh
udrcver.sh
run udrcver.sh
cd to root then above
THANKS


Basil Gunn
 

Check that the SMA GPS antenna connector is screwed on tight. Some RPi
cases will prevent the GPS antenna from connecting properly. Make sure
the center pin of the connector is not bent.

Don't stop gpsd !!
gpsd is meant to start running from boot and remain running.

Reboot your system and verify that gpsd is running by running the following:

systemctl status gpsd

Console output should look as below, look for "active (running)"

● gpsd.service - GPS (Global Positioning System) Daemon
Loaded: loaded (/lib/systemd/system/gpsd.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2021-03-28 16:06:45 PDT; 5h 43min ago
Process: 647 ExecStart=/usr/local/sbin/gpsd $GPSD_OPTIONS $OPTIONS $DEVICES (code=exited, status=0/SUCCESS)
Main PID: 662 (gpsd)
Tasks: 3 (limit: 4915)
CGroup: /system.slice/gpsd.service
└─662 /usr/local/sbin/gpsd -n /dev/ttySC0 /dev/pps0

Mar 28 16:06:45 test119013021 systemd[1]: Starting GPS (Global Positioning System) Daemon...
Mar 28 16:06:45 test119013021 systemd[1]: Started GPS (Global Positioning System) Daemon.

Kk6qms <kk6qms@arrl.net> writes:

I have used the DRAWS manager to stop the GPSD service-
Why?
connect one of the 2 antennas (I marked them 1 and 2) and restart the
GPSD service. Neither antenna gets a fix after 10mins.
Check your antenna connection.

I then shutdown the DRAWS station- connected each antenna- and waited
10mins. Neither obtains a fix in CGPS or GPSMON. I really do not
understand why results are so unpredictable up to this point.


Kk6qms
 

On Sun, Mar 28, 2021 at 09:59 PM, Basil Gunn wrote:
systemctl status gpsd
1- I am using the aluminum DRAWS early adopter case. No issue there.

2- gpsd is good- almost 4hrs- no fix (I stopped/restarted it in the idea I was closing/reopening to troubleshoot not from any inherent wisdom haha):
"root@DRAWSpi:/home/pi# systemctl status gpsd
● gpsd.service - GPS (Global Positioning System) Daemon
   Loaded: loaded (/lib/systemd/system/gpsd.service; enabled; vendor preset: ena
   Active: active (running) since Sun 2021-03-28 18:20:40 PDT; 3h 41min ago
  Process: 603 ExecStart=/usr/sbin/gpsd $GPSD_OPTIONS $DEVICES (code=exited, sta
 Main PID: 608 (gpsd)
    Tasks: 3 (limit: 3738)
   CGroup: /system.slice/gpsd.service
           └─608 /usr/sbin/gpsd -n /dev/ttySC0 /dev/pps0
 
Mar 28 18:20:40 DRAWSpi systemd[1]: Starting GPS (Global Positioning System) Dae
Mar 28 18:20:40 DRAWSpi systemd[1]: Started GPS (Global Positioning System) Daem
lines 1-11/11 (END)"

3- I am using a fresh NWDR image- I verified udrcver.sh is in the dir but I get no output:
"root@DRAWSpi:/home/pi/bin# which udrcver.sh
root@DRAWSpi:/home/pi/bin# "

4- I think I used the "nwdr19.img.xz" not the "current_image.xz" I am downloading the former and will start from scratch.

Thank you both for the help and appreciate the extra info on ./ info and links. I am always learning more about Linux.

Clifford