Having trouble wrapping my head around some of this.
Let’s say me and my friends all have a Secondary channel set up with a matching key and name. We live too far away from each other for LoRa to work so we use Mqtt. But, we are on different Mqtt topics across the state. Will this still work or does the Mqtt topic have to match also?
I am no expert. I have been trying MQTT out. I have found if I am on msh/US/CT topic then no nodes are added. However, if I am on msh/US topic then a lot of nodes are added. In my opinion, all of the nodes using MQTT have to be on the same topic.
There is another recent topic on MQTT and secondary channels. It appears MQTT uses the primary channel for communication. Here is the topic: MQTT only working on the default channel? - #7 by chrisj If I am wrong, hopefully, someone will provide the correct information. I hope this is a help.
MQTT topics have to match in order for devices to be visible to each other over MQTT.
Much of my confusion in the other thread had to do with the matter of the primary channel. It turns out that the primary channel is always channel zero. Nodeinfo packets go out on the primary channel, so apparently nodes won’t see each other unless they have the same primary channel. They can still communicate, though, providing they can address each other.
This whole issue could use some official clarification for sure. I have been experimenting for many weeks and am still a bit uncertain about how channels work. They seem to be the most confusing part of Meshtastic.
What is interesting is when I watch the server in Mqtt Explorer.
I am currently set to msh/US/GA. But I am broadcasting across several subfolders, */2/map/, */2/e /LongFast, etc…
and, if I send a message over a secondary channel, it goes to msh/US/GA/2/“secondary channel name”
Am I correct that it broadcasts to all subfolders of the Primary topic?
It broadcasts to all the subtopics under the topic to which you have published.
As far as I can tell.