Comments on: Raspberry Pi Buster – GPS Dongle as a time source with Chrony & Timedatectl https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/ Freelance Technical Author, Illustrator & Photographer Mon, 13 Jan 2025 00:57:19 +0000 hourly 1 https://wordpress.org/?v=6.8.1 By: Mike Richards https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-567564 Mon, 13 Jan 2025 00:57:19 +0000 https://photobyte.org/?p=1746#comment-567564 In reply to Chuck.

Hi Chuck,

I’m sure you’re correct but I haven’t reviewed this post for a long time. When I get a spare moment, I’ll check the instructions on a Pi 5 and update the installation steps.

Thanks for letting me know.

Mike – G4WNC

]]> By: Chuck https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-567537 Sun, 12 Jan 2025 19:29:02 +0000 https://photobyte.org/?p=1746#comment-567537 Thanks.
My Raspberry PI5 now sets time from GPS.
Great tutorial.
One note though
I did not include these two items, python-gps chrony python-gi-cairo, since they don’t seem to exist for PI5. Other than that, the tutorial is spot on. Worked first time!
Thanks for a painless afternoon.

]]> By: Lonney https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-499047 Wed, 24 Apr 2024 15:56:12 +0000 https://photobyte.org/?p=1746#comment-499047 In reply to Lonney.

I figured out the problem with this, this is how I solved it:

Plug the GPS in

sudo dmesg

Note the /dev/ttyUSBx device name the GPS was mounted with.

ls -l /dev/serial/by-id/

Note the name of the link pointing to the /dev/ttyUSBx device name.

sudo apt-get install gpsd gpsd-clients

Edit /etc/default/gpsd to match

START_DAEMON=”false”
USBAUTO=”false”
DEVICES=”/dev/serial/by-id/usb-Prolific_Technology_Inc._USB-Serial_Controller_D-if00-port0″
GPSD_OPTIONS=”-n -G -b”
GPSD_SOCKET=”/var/run/gpsd.sock”

DEVICES matches the GPS serial link name, one line.

USBAUTO=”false” disables hot plugging. If enabled (true) gpsd will attempt to get GPS data from any serial device that is connected and prevents other applications from accessing the port, including the radio USB port!

]]> By: Lonney https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-489488 Mon, 12 Feb 2024 02:39:15 +0000 https://photobyte.org/?p=1746#comment-489488 In reply to Roger.

I had the same issue. Rig on /dev/ttyUSB0 and GPS on /dev/ttyUSB1, the problem seems to be when gpsd starts on system boot it locks up /dev/ttyUSB0 and the radio wont work. I found restarting gpsd would fix it, or another possibility might be to let gpsd use USB0, and configure the radio on USB1.

You can see which dev has been assigned by looking at dmsg output after connecting the device.

]]> By: Roger https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-361111 Sun, 26 Jun 2022 16:57:17 +0000 https://photobyte.org/?p=1746#comment-361111 Hi Mike

Installed GPS as per your instructions and seems to work fine. However, a direct side-effect of installing the GPS software is that Flrig is now unable to communicate with my IC7100.
This appears to be caused by a USB conflict, but not sure how to resolve it. Have you encountered this issue and can you suggest a resolution?

73 de Roger.

]]> By: Didier B https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-306962 Wed, 16 Mar 2022 14:15:49 +0000 https://photobyte.org/?p=1746#comment-306962 Used this with Raspi OS 64. Everything is going fine, python-gi-cairo can no longer be found, but doesn’t prevent xgps to work. Probably integrated in Debian 64 at last …
The only little issue I met, is that after a reboot, I will first get in answer to the ‘chronyc sources -v’ command the following : ‘#? NMEA …’ repeatedly until I use a gpsd client, e.G. cgps, then I will find the so awaited for ‘#* NMEA …’
Even interrogating ‘sudo systemctl is-active gpsd’ is enough to make everything all right.
Most probably the source of the issue is in gpsd itself, as I had allready seen the same phenomena in OpenCPN (need to launch a gpsd client before getting any NMEA data in OpenCPN

]]> By: JohnM https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-304541 Tue, 08 Mar 2022 16:03:32 +0000 https://photobyte.org/?p=1746#comment-304541 In reply to JohnM.

reflock, oh, should be refclock!!

]]> By: JohnM https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-304540 Tue, 08 Mar 2022 16:00:17 +0000 https://photobyte.org/?p=1746#comment-304540 Hi Mike, thanks for the tutorial! I have cgps working, chronyd and gspd active, but only as long as I don’t have the reflock line in chrony.conf. I am having an issue when I add the reflock line to the /etc/chrony/chrony.conf file. It tags the reflock line as “invalid directive”, whatever that means.
My /run/gspd.sock file is empty, always. What is the purpose of this file? What should it contain?
My device is a USB dongle by TSI (GM-3N) based upon the MTK MT3333 chip. It does not support PPS outputs via NMEA (firmware is too old).

]]> By: David https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-297477 Sun, 13 Feb 2022 09:53:18 +0000 https://photobyte.org/?p=1746#comment-297477 This helped a lot! Especially the part about commenting out “START_DAEMON” and simply adding “refclock SHM 0 offset 0.5 delay 0.2 refid NMEA” to chrony’s config did the trick!

]]> By: Sean Mac Suibhne https://photobyte.org/raspberry-pi-stretch-gps-dongle-as-a-time-source-with-chrony-timedatectl/#comment-278570 Fri, 17 Dec 2021 16:33:02 +0000 https://photobyte.org/?p=1746#comment-278570 Sorry I see I introduced a typo there at the end of the third line.
Replace the ? with a ”
# START_DAEMON=”true” ( Comment this line out )
USBAUTO=”true”
DEVICES=”/dev/ttyACM0″
GPSD_OPTIONS=”-n”

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