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GNSS

Satellite positioning is implemented using a NEO-M9V receiver. The receiver is connected to the navigation Raspberry Pi.

Additional installation

sudo apt install gpsd gpsd-clients libgps-dev

Support added to teensy_interface (not fully tested) - part of Robobot software.

Raspberry Pi issue

Starting gpsd as a service fails, but manually starting it works fine:

sudo gpsd -n -N -D3 /dev/ttyACM1

Starting the service fails, like:

local@Saturn:~ $ systemctl status gpsd
○ gpsd.service - GPS (Global Positioning System) Daemon
    Loaded: loaded (/usr/lib/systemd/system/gpsd.service; enabled; preset: enabled)
    Active: inactive (dead)
TriggeredBy: × gpsd.socket
      Docs: man:gpsd

Apr 26 13:02:52 Saturn systemd[1]: Dependency failed for gpsd.service - GPS (Global  Positioning System) Daemon.
Apr 26 13:02:52 Saturn systemd[1]: gpsd.service: Job gpsd.service/start failed with result 'dependency'.

After a long search by Ecosia, I found a fix.

The /lib/systemd/system/gpsd.socket looked like this:

[Unit]
Description=GPS (Global Positioning System) Daemon Sockets

[Socket]
ListenStream=/run/gpsd.sock
ListenStream=[::1]:2947
ListenStream=127.0.0.1:2947
# To allow gpsd remote access, start gpsd with the -G option and
# uncomment the next two lines:
ListenStream=[::]:2947
ListenStream=0.0.0.0:2947
SocketMode=0600
#BindIPv6Only=yes
BindIPv6Only=both

[Install]
WantedBy=sockets.target

Then uncommented most of these dependencies to listen to only 127.0.0.1:2947:

[Unit]
Description=GPS (Global Positioning System) Daemon Sockets

[Socket]
ListenStream=/run/gpsd.sock
#ListenStream=[::1]:2947
ListenStream=127.0.0.1:2947
# To allow gpsd remote access, start gpsd with the -G option and
# uncomment the next two lines:
#ListenStream=[::]:2947
#ListenStream=0.0.0.0:2947
SocketMode=0600
#BindIPv6Only=yes
#BindIPv6Only=both

[Install]
WantedBy=sockets.target

Then I could do

systemctl start gpsd

and verify with

cgps

Decode and publish

Using the 'gpsd' publisher. This should be easily interfaced to ROS.

see: https://kickstartembedded.com/2022/07/23/a-beginners-guide-to-using-gpsd-in-linux/