4.9 KiB
4.9 KiB
GPS
Location fun. Tracking, logging, etc
Inspiration / Further Reading
- https://github.com/wadda/gps3
- https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi?view=all
- https://learn.adafruit.com/assets/3715
- https://learn.adafruit.com/adafruit-ultimate-gps?view=all
- https://stackoverflow.com/questions/16989153/saving-gps-data-as-gpx
- http://www.catb.org/gpsd/gpspipe.html
- http://www.catb.org/gpsd/gpsd-time-service-howto.html#_feeding_chrony_from_gpsd
- http://thomasloughlin.com/gpspipe-gps-client/
- http://robotsforroboticists.com/chrony-gps-for-time-synchronization/
- https://forum.armbian.com/topic/4944-opi-zero-gps-ntpserver/
- http://darethehair.net/gps_time_server.html
- https://forum.armbian.com/topic/7033-solved-orangepi-one-1-pps-ntp-server/
- https://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html
Hardware
The author chose the Adafruit Ultimate GPS Breakout (link) for this guide. YMMV with other boards.
Pinout
- Connect vcc to a 3v source on the main expansion header
- Connect gnd to a gnd on the main expansion header
- Connect tx to rx pin of uart2 on the main expansion header
- Connect rx to tx pin of uart2 on the main expaions header
- Connect pps to the PA6 pin on the main expansion header
Setup
armbian-config # Enable hardware uart2 and pps-gpio
# System
# Hardware
# Enable uart2 option
# Enable pps-gpio option
# Save/reboot
apt install gpsd gpsd-clients python-gps gpsbabel # necessary software
systemctl stop gpsd # stop gpsd to help with testin
gpsd -n -N -D 2 /dev/ttyS2 # run gpsd by hand
cgps -s # run a cli client to verify it works
Setup necessary gpsd
defaults (daemon that provides location data to programs).
Edit /etc/default/gpsd
- Add
/dev/ttyS2
toDEVICES
- Add
-n
toGPSD_OPTIONS
Chrony
Setup PPS for chrony
cat >> /boot/armbianEnv.txt <<EOF
param_pps_pin=PA6
EOF
systemctl reboot
demsg | grep -i pps # Verify pps is enabled and shows in the kernel
Add GPS as a time source to chrony
cat >> /etc/chrony/chrony.conf <<EOF
# set larger delay to allow the NMEA source to overlap with
# the other sources and avoid the falseticker status
refclock SHM 0 refid GPS precision 1e-1 offset 0.9999 delay 0.2
refclock PPS /dev/pps0 lock NMEA
EOF
systemctl restart chrony
cgps # look for ```Status: 3D FIX```
chronyc sources -v # Should show PPS and GPS time sources as having a recent reading
chronyc tracking # Further details
GPX Tracks
NextCloud
GpxPod for NextCloud is a good viewer for GPX track recordings
Tracking
gpspipe -r -d -l -o /tmp/xxx.nmea
will record the raw GPS data from the module. Can be used for tracking.
GPX Files
You can convert raw nmea
data from gpspipe
using gpsbabel
Examples
gpsbabel -t -r -w -i nmea -f /tmp/xxx.nmea -o gpx -F xxx.gpx
gpsbabel -t -i nmea -f /tmp/xxx.nmea -x track,pack,split=5m,title="LOG # %Y%m%d-%H%M" -o gpx -F out.gpx
Automatic Logging
The Python program used here is in the scripts
directory.
mkdir -p /tank/gps_data
chown -R gpsd:root /tank/gps_data
# put gpslog.py at /usr/local/bin
cat > /etc/systemd/system/gps-logger.service <<EOF
[Unit]
Description=Simple gps logger
After=gpsd.service gpsd.socket
[Service]
User=gpsd
ExecStart=/usr/local/bin/gpslog.py
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl enable gps-logger
systemctl start gps-logger
Setup Auto GPX Track Creation/Upload
A handy trick for auto-converting your GPS log data as well as uploading it to NextCloud. The Python program used here is in the scripts
directory.
cat > /etc/systemd/system/gpsconvert.service <<EOF
[Unit]
Description=Merge GPS logs and upload to NextCloud
After=gps-logger
[Service]
ExecStart=/usr/local/bin/gpsconvert.py
EOF
cat > /etc/systemd/system/gpsconvert.timer <<EOF
[Unit]
Description=Run GPS log merge
[Timer]
OnCalendar=hourly
Persistent=true
[Install]
WantedBy=timers.target
EOF
systemctl daemon-reload
systemctl enable gpsconvert.timer
systemctl start gpsconvert.timer