Is there a documentation resource which describes precisely what all the default values published to an MQTT broker are? Values such as pmO2Compensated, etc and what their default compensations are?
Hi @adam_burns! Welcome to the community and thank you for your question!
At the moment, I don’t think there’s a dedicated document describing the MQTT parameters but I’m working on such a document describing all the parameters which should help - I will update with a link here once it’s ready!
In general, the compensated values are corrected according to the correction selected in the dashboard. Perhaps @Ethan_AirGradient can help me here by adding more context. (Thanks @Ethan_AirGradient!)
Hi @adam_burns, @Altair_AirGradient,
Yes, the compensated values will show the PM2.5 concentration with the corrections that are applied in your dashboard. This can be a sensor batch correction, and/or the EPA correction.
We can provide a full document with the parameters in the near future!
Hi @Ethan_AirGradient , @Altair_AirGradient,
Thanks for your responses.
As I’m not sure yet how to configure locally, I configured an AirGradient One via app.airgradient.com to publish to mqtt://kodi-pi.zenr.io:1884
(side note: entering mqtts://kodi-pi.zenr.io:8884 with the mosquitto broker configured with a Let’s Encrypt certificate does not appear to function)
From the current firmware, the only MQTT topic received appears to be of the form airgradient/readings/<#serial number> with payload typical of example below:
{
“tst”: “2025-08-05T13:25:56.914002+0200”,
“topic”: “airgradient/readings/d83bda1b0e5c”,
“qos”: 0,
“retain”: 0,
“payloadlen”: 483,
“payload”: “{“pm01”:0.5,“pm02”:1.17,“pm10”:1.17,“pm01Standard”:0.5,“pm02Standard”:1.17,“pm10Standard”:1.17,“pm003Count”:204,“pm005Count”:180.33,“pm01Count”:34.67,“pm02Count”:4,“pm50Count”:0,“pm10Count”:0,“pm02Compensated”:7.88,“atmp”:22.04,“atmpCompensated”:22.04,“rhum”:65.55,“rhumCompensated”:65.55,“rco2”:430.33,“tvocIndex”:1.5,“tvocRaw”:32925.58,“noxIndex”:0.5,“noxRaw”:18743.42,“boot”:0,“bootCount”:0,“wifi”:-44,“ledMode”:“co2”,“serialno”:“d83bda1b0e5c”,“firmware”:“3.3.9”,“model”:“I-9PSL”}”
}
It might be worth considering documenting MQTT published topics and payloads with or for each released firmware version?