CODEWITHSUNDEEP
linuxgpsudpmulticastgpsd
Thom Armax
Thom Armax

Reputation: 147

GPSD and UDP multicast feed

I'd like to configure GPSD to take as input an UDP multicast stream. I have a background service which sends NMEA frames on UDP multicast, port 5098 (254.0.0.50:5098)

I've tried :

gpsd udp://254.0.0.50:5098 -n -N -D 5

but it's not working. Here is the result :

gpsd:INFO: launching (Version 3.9)
gpsd:IO: opening IPv4 
gpsd:IO: opening IPv6 socket
gpsd:INFO: listening on port gpsd
gpsd:PROG: NTPD shmat(0,0,0) succeeded, segment 0
gpsd:PROG: NTPD shmat(32769,0,0) succeeded, segment 1
gpsd:PROG: NTPD shmat(65538,0,0) succeeded, segment 2
gpsd:PROG: NTPD shmat(98307,0,0) succeeded, segment 3
gpsd:PROG: successfully connected to the DBUS system bus
gpsd:PROG: PPS thread launched
gpsd:INFO: NTPD ntpd_link_activate: 1
gpsd:INFO: stashing device udp://254.0.0.50:5098 at slot 0
gpsd:PROG: no /etc/gpsd/device-hook present, skipped running ACTIVATE hook
gpsd:INFO: opening UDP feed at 254.0.0.50, port 5098.
gpsd:PROG: PPS Create Thread gpsd_ppsmonitor
gpsd:PROG: PPS thread awaiting device activation
gpsd:ERROR: UDP device open error can't connect to host/port pair.
gpsd:ERROR: initial GPS device udp://254.0.0.50:5098 open failed
gpsd:PROG: PPS thread awaiting device activation
gpsd:INFO: running with effective group ID 20
gpsd:INFO: running with effective user ID 65534
gpsd:INFO: startup at 2015-05-05T13:38:33.000Z (1430833113)
gpsd:PROG: PPS thread awaiting device activation

Do you have an idea where I'm wrong ?

Thanks by advance.

Sincerely.

Thom

Upvotes: 1

Views: 2848

Answers (2)

FransVeldman
FransVeldman

Reputation: 11

I had exactly the same problem. I was trying to use an UDP multicast coming from 192.168.1.100 port 10110, but using gpsd udp://192.168.1.100:10110 -n -N -D 5 didn't work, neither did listening on localhost. After much research I found that it works by using gpsd udp://192.168.1.255 -n -N -D 5 Note that 192.168.1.255 is a non-existent ip on my network. It seems that gpsd is only able to fetch UDP multicast messages from the non-existent .255 node.

Upvotes: 1

dbush
dbush

Reputation: 224082

254.0.0.50 is not a valid multicast address.

Valid IPv4 multicast addresses are in the range 224.0.0.1 - 239.255.255.255. Addresses in the range 240.0.0.0 - 255.255.255.255 are reserved.

Upvotes: 0

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