Passing a hex string to a payload decoder in Node-RED

[arjanvanb (Arjan)]

This may help?

@arjanvanb

To get the LoRaWAN application payload bytes and port, just like in a Decoder in TTN Console’s payload formats:

// When using a Decoder in the application's Payload Formats in
// TTN Console, then msg.payload.payload_fields is also available.
const bytes = Buffer.from(msg.payload.payload_raw, 'base64');
const port = msg.payload.port;

And indeed, when using Node-RED already, I’d not use the payload formats in TTN Console anymore.

Aside, note that a LoRaWAN application payload is really an array/buffer/list of bytes, so: values from 0 to 255. Hexadecimal is just one (of the many) human-readable representations of that.

Aside: your decoder does not support negative temperatures. See the post I quoted from above for a fix.