Node-RED/Grafana "No measurement specified"

Application Development
10

It seems this uses the event topic? That is not giving you uplinks, hence also does not give you payload_fields; see the MQTT Data API documentation.

The fact the message only holds a single gateway_id also tells you it cannot be an uplink, as that might be received by multiple gateways. Actually, using an online decoder you’ll see that this is the AU915 initial ADR downlink, like discussed in your previous LMIC Library Always Does Unwanted Downlink.

Above, despite the name temperature this actually holds all payload fields. To explicitly get the values, use something like:

return {
    t: msg.payload_fields.temperature,
    h: msg.payload_fields.humidity 
};

Or, if you don’t want to change any names, simply:

return msg.payload_fields;

See What to do with the raw payload via MQTT? and Advantage of Base64 encoding in MQTT?

And given some problems people are having with authentication using the TTN Node-RED library, see also Node-RED "Error: 14 UNAVAILABLE: Connect Failed" when using node-red-contrib-ttn - #12 by GeorgeKroon, which you can avoid by using Node-RED’s built-in MQTT.

Beware that your Decoder does not support negative temperatures. And your sensor is probably not accurate enough for any decimal digit in humidity.

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