Sending device data to another program

I have a RAK7244 gateway running Chirpstack US915 @ 3.14.0. I have two LHT65 temp/hum sensors sending data and all seems to be working correctly on my home LAN.
I see the following data as part of the device data being displayed in the gui (localhost:8080):

Applications / LHT65 / Devices / LHT65x
Device Data
Aug 30 10:15:44 AM up 904.7 MHz SF10 BW125 FCnt: 197 FPort: 2 Unconfirmed
objectJSON: {} 5 keys
Ext_sensor:“Temperature Sensor LHT65”

How can I send this data to another program on another linux machine? I’m running both weewx (weather program) and emoncms (energy monitor) and would like to make this data available to one of these programs.

I’m not a programmer and am not sure how to approach this. Is chirpstack creating a json file somewhere on the RAK7244 which can be sent to another program to be parsed?

Any help and/or suggestions would be appreciated. Thanks.

You get something like Node-RED to subscribe to the broker. This lets you act on the data before forwarding it to your other programs and/or save it to a TXT file which those programs can then read. You can find folks rolling their own clients in Linux.

THIS explains what’s going on in a general, easy to understand way. Steve has a page for all MQTT that’s a good reference.

Many thanks for the suggestions and links. Since I’m not very knowledgable in this area I have a few simplistic questions. Let’s say I have a weather program running on an rpi on the same LAN:
Do I set up a node-RED instance on the rpi to subscribe to the data being sent to the RAKgateway?
What topic am I looking for on the RAK chirpstack? I can see the data coming in but so far haven’t been able to find where it’s located or what form it’s in. The objectJSON is formed somewhere but I’m at a loss here to find it.
Sorry for the ignorance but I’m trying to learn.
Much appreciated for taking the time with this.

Node-RED makes things simple so I’d recommend it as the project. It’s very stable - I’ve run it for months (10-14) without any problems. Often browser looking at the ui would run out of memory but that’s not Node-REDs fault :slight_smile:

I have used MQTTExplorer for casual exploring streams and also troubleshooting. Initially, you’ll want to subscribe to # (everything) and then see what you want to filter on. Your broker’s URL/interface depends on how you set it up; these instructions worked great for me. For reference, my broker URL is “tcp://<IP>:1883”

Node-RED runs on RPi so check official docs or THIS for someone’s project. Also, THIS search will get you started.

Thanks again. Let me see how much of this I can digest without asking a question. I understand what is going on (I think…) but to build/configure my own setup between the Rak7244 and another rpi appears daunting at first glance.