Questions tagged [gpsd]

Questions pertaining gpsd, a daemon that receives data from a GPS receiver, and provides the data back to multiple applications such as Kismet or GPS navigation software.

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Unable to read data from gpsfake

I saved the following NMEA-messages to the file messages.txt: $GPRMC,131131.00,A,5956.4298,N,03015.4464,E,00.00,310.5,130123,,,D*53 $GPRMC,131132.00,A,5956.4298,N,03015.4464,E,00.01,097.3,130123,,,D*...
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Read NMEA messages in ntpd to adjust system time

I want to configure ntpd so that it reads NMEA messages from an HTTP-server and uses their time to adjust system time. For that I did the following. Stored the following NMEA-messages in messages.txt: ...
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What should be the reason for PTP for not able to access shared memory?

I'm using yocto rootfs where I have installed linuxptp, chrony, and gpsd. So I'm trying to use the shared memory 2 for ptp by using following file /etc/ptp4l.conf [global] # only syslog every 1024 ...
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Why still chrony is not taking time from PPS after 197 hours?

I'm using chrony where GPSD and the PPS will be used for accurate timings. my chrony.conf file as follows, refclock SHM 0 delay 0.8 refid NMEA trust prefer ...
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Issues Using GPSD as Source for Chronyd

I am attempting to use a USB GPS without PPS dongle as the sole time source on Ubuntu 18.04. GPSD appears to be working correctly since cgps reports a 3D fix. However, I can't get chrony to see the ...
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Using gpsd and chrony without pulse per second

Inspired by this answer: https://askubuntu.com/a/1374637 I'm attempting to get chrony to get its time from gpsd without a pulse per second. I am aware that https://gpsd.gitlab.io/gpsd/gpsd-time-...
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What will be the reason for GPSD not working in chrony?

I'm trying to sync PPS with GPSD using chrony but I'm getting '#?' before gps what will be the reason? my chrony.conf file is, # Welcome to the chrony configuration file. See chrony.conf(5) for more # ...
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1 answer
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PPS on focal/20.04 timed out and never recovers

we recently have upgraded to a new industry PC from Vecow/Plugin and to Ubuntu 20.04 from 18.04. From the BIOS (build date BIOS ~17.02.2022) and the IO chip according to it is a SuperIO 8786: https://...
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GPSD, How to get the last known location?

if GPS-module disconnected, or if GPS antenna gets moved into building, I wan't to know the last available location. I tried to log location every 10 or so seconds with systemd-timers; However, ...
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Reading file that other processes overwrite sometimes

I wrote a systemd-service/timer that will be update GPS location at using gpscsv --header 0 -n 1 > /tmp/location every 10 or 15sec. when I inspect the text file with watch -n 1 cat /tmp/location, ...
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Creating an isolated NTP server with only 1PPS and no external "time" input (No GPS)

Am looking to have a small NTP server (Chrony) provide time to different computers located on the same student under water vehicle connected via ethernet cables. We are primarily concerned with having ...
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Trouble connecting UART device via USB Port

Im trying to communicate with a couple of UART devices via USB. A HT-06 bluetooth module and a GY-NEO6MV2 GPS module. I am using a Prolific PL2303 USB cable. As a backup I also have a Silicon Labs ...
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Why is GPSd clients not returning data?

I'm using a Neo-M9N to get the latitude, longitude, speed, and so on and place these values in a csv file. I installed the gpsd python clients. I'm able to view the data only using gpsmon /dev/ttyTHS1 ...
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Emulating an AARCH64 Binary calling libgps on x86_64 Ubuntu using QEMU gives "Error relocating: symbol not found" Errors

This is similar to the issue posted here and here. I want to reverse engineer a binary called gpslogger but before debugging it using GDB, I wish to simply emulate it using QEMU (qemu-aarch64) since ...
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gpsd fails to start on boot, but does manually

Ok, I know there are variations of this problem out there. I have looked at nearly every one that looks like it might be pertinent and nothing works. I have a USB serial device that I set up to be on ...
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1 answer
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Feeding "mixed" NMEA to NTP for time correction

I am trying to correct the time on my Raspberry pi by feeding NTPD with GPS nmea data (via serial) and PPS (via GPIO pin) using the following tutorial via shared memory "SHM". http://www.unixwiz.net/...
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GPS starts emitting data as soon as I kill GPSD

I can't really figure out how GPSD works. If I start gpsmon nothing happens. But if I run sudo killall gpsd immediately position starts to appear on screen. The same happens in my node app. I start ...
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GPS device not detected by gpsctl

My GPS device (/dev/ttyUSB2) outputs NMEA sentences when connected to with minicom or cat, but when using gpsctl with gpsd (running gpsd /dev/ttyUSB2) the following output is generated: gpsctl: no ...
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preventing udev symlink overwrite

I built a PPS-capable GPS clock on my Raspberry Pi, and to get it to work, I needed to use udev to create symlinks to the hardware serial port and the kernel GPIO PPS on /dev/gps0 and /dev/gpspps0. ...
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1 answer
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How do I interpret the results of gpscat? [closed]

I've been trying to get gps data from an embedded system. This is the command I use: gpscat /dev/ttyS2 And I get a continuous stream of output like this: $GLGSV,1,1,03,70,14,098.6102,E,121853.000,...
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1 answer
1k views

How do I use gpsdecode to output the results of gpscat in a readable manner?

I am connected to a processor with GPS attached through a USB-serial port. What I've been trying to do is read the GPS data by doing: gpscat /dev/ttyS2 | gpsdecode However, it's very slow and after ...
2 votes
1 answer
1k views

How to read NMEA data from the Holux M-1200 GPS receiver

I have a Holux M-1200 GPS receiver and a pl2303 data cable. The cable appears as /dev/ttyUSB0, but when I turn on the receiver and cat /dev/ttyUSB0 the device, only random symbold appear, like this: ...
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gpsd on CentOS 7 not working after yum install

I've installed gpsd 3.10 (also tried 3.16) on CentOS 7 Minimal (yum install gpsd). The following dependencies have been pulled in as well: bluez-libs, gpsd-libs, libusbx. It seems to start up fine ...
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How to add a custom GPS location to a picture?

Given a .jpg picture without associated GPS coordinates, how would you suggest to add custom coordinates to it?
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Running Script on GPS Fix

I am working on an embedded device which is designed to capture images and I want to make it time and location aware. The device is currently a raspberry pi 2 running Debian Jessie. I have GPS set up ...
3 votes
1 answer
7k views

using GPS with Linux & output only certain data

Hello I am currently using BU-353 S4 USB GPS in my Linux, the command, cgps -s Output various parameters including, Time, Latitutde, Longitute, Speed, Heading etc... is there any way to output ...
2 votes
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844 views

How to resume the ?WATCH command when a USB GPS is reconnected

I have some hacks to ensure that my USB GPS devices continues spitting data if disconnected, then reconnected. The devices are so flaky that they need restarting so as to continue transmitting data. ...
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7 votes
2 answers
6k views

How to get ntp to use gpsd to update system date/time with a large offset

I have a GPS connected to my system, and if I change system time to be ahead/behind GPS time by less than 4 hours, ntpd ensures that the system time is updated to match that of the GPS. If, however, ...
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