What is the correct way to send to mesh from mqtt now?

Support
1

Since pull req 3141 (docs:951), the established way to send to the mesh doesn’t work unless the channel is named “mqtt”. Obviously I don’t want to rename my private channels to “mqtt” (and I use more than one, so there’s a naming conflict). What is the correct way for an integration (in say node red) to send a message to a channel?

2

Note that this only holds if you’re using JSON. If you’re using protobufs, nothing has changed.
If using JSON, just add a new channel called “mqtt” and publish the JSON message as described here to that topic. You can optionally add a field “channel” with an index (0-7) to instruct the node which channel to use.

3

Oh, so it’ll still honour the channel index in the JSON and the “mqtt” channel is just a permission mechanism?

4

Correct, it has to be published to the “mqtt” channel, but you can still instruct it to send it out anywhere.

5

I still do not get it. Please help.

  1. I have device connected over WiFi.
  2. two channels are configure, one primary “HANAX” and one secondary “mqtt”. Both have uplink and downlink enabled (Is this necessary for both?)
  3. When I send message from device, I can see mqtt in node-red from primary channel on the topic “msh/EU_868/2/json/HANAX/!75f184e4”. Great, this works. Also, I can see telemetry messages.

Now to send text to mesh:

I send message to topic “msh/EU_868/2/json/mqtt”. The message is:

{
    "from": 1978762468,
    "type": "sendtext",
    "channel": 0,
    "payload": "TEST!!"
}

but nothing happens :frowning: What is the problem?

Edit: After more trials I resolved it.
I found out that I need to use node number “msh/EU_868/2/json/mqtt/!75f184e4” in the topic. Maybe more concrete wording in the documentation will be useful.

6

The node number shouldn’t be needed. Not sure what changed, but it should also work like you tried previously.

7

Yes, it is not so flexible, but since I have no plan to change the node, I do not mind that it is “hard wired”. At least it works.

Regarding uplink and downlink status of botch channels, now I have uplink on primary and downlink on mqtt. It works, but I wonder if it was meant to have it set up that way.

8

You could try sending to msh/EU_868/2/json/mqtt/ now once more, it should work.

Yes, downlink should be on on the channel “mqtt” to be able to instruct a node to send something out. If you want that to uplink to MQTT, you also have to enable that on the primary, yes.

9

Yes, you are right. It’s working, the ending “/” was missing. Great! Thanks.