More MQTT data information

ChirpStack Application Server
1

Hello,
I am using the Chirpstack application server with a localhost MQTT connection to retrieve data from my object.
Current forwarded messages are providing the following information:

{
“applicationID”: “1”,
“applicationName”: “app_123”,
“deviceName”: “device-123”,
“devEUI”: “123456789”,
“rxInfo”: [
{
“gatewayID”: “aa555a0123456789”,
“uplinkID”: “c7276e2e-3e9f-4f09-84f5-348086e6eeb0”,
“name”: “gateway-123”,
“rssi”: -50,
“loRaSNR”: 10,
“location”: {
“latitude”: 0,
“longitude”: 0,
“altitude”: 0
}
}
],
“txInfo”: {
“frequency”: 868300000,
“dr”: 0
},
“adr”: false,
“fCnt”: 4,
“fPort”: 2,
“data”: “AAA”
}

I would ideally like more info such as the channel, crcStatus, spreading factor, devAddr (these information can be seen via the web app so I believe it is just a matter of what’s being forwarded via MQTT).

How do I achieve that ?

Thank you, Adrien M.

1 Like
2

In your chirpstack-application-server.toml you will find a config option marshaler, set this to json instead of json_v3. See also: Event types - ChirpStack open-source LoRaWAN<sup>®</sup> Network Server.

1 Like
3

Hello Orne,
Thank you for the advice, the modification worked well.
Regards,
Adrien M.

4

@brocaar Thank you for your work and your comment on changing the MQTT Integration marshaler.

Unfortunately, after changing the marshaler to json from json_v3 no additional LoRa metadata was provided. We are specifically interested in the SF (Spreading Factor) of the uplink, which is the only metadata we are missing for our use case.

Server Information

OS: Debian 10 (x86_64)
ChirpStack Gateway Bridge Version: 3.13.3
ChirpStack Network Server Version: 3.16.1
ChirpStack Application Server Version: 3.17.6

I understand this issue was opened almost 2 years ago so, with a newer ChirpStack version, this feature might not exist anymore or has been changed. Either way, do you know how we could retrieve the SF for each uplink with the MQTT integration.

Thank you.

5

This data is exposed, you should see an rxInfo array:

image

If that is empty, please check your service-profile settings.