Re: Broadcast nmea to the network

[Gary E. Miller]

Yo Andreas!

On Mon, 18 Mar 2024 15:02:03 +0100
Andreas B <panden@gmail.com> wrote:

> The reason why I want to test this (it's all for fun), is that I've
> seen it done on vessels (ships, acquiring e.g. echosounder data).
> Instead of clients connecting to a server, the device responsible for
> location data (i.e. GPS/GNSS) will send datagrams (containing NMEA
> sentences) to the network broadcast address.

Yeah, not uncommon, there and in other applications.  But using UDP is
not a good idea.

And NMEA is a mess.  So much so that many new GNSS receivers prefer their
own protocol.  Better to let gpsd decode it all to a nice common JSON for you.

>  In my naive case, rogue
> devices spraying bogus data do not exist.

Hahaha, thanks for the laugh!

> To me this seems simple and efficient: if you care about the data,
> all you have to do is listen. A downside is of course that you're,
> well, broadcasting data to the whole network.

And modern IP switches make broadcasting harder and harder.  "Enterprise"
switches often disable broadcast by dwfault.

> Mosquitto/MQTT looks interesting.

Yes, it is very neat.

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

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