I have a question about selecting one payload_fields signal in function node, so the MQTT OUT node can only output one signal such as humidity. But in fact, in my TTN console, the downlink massage is always 00000000000, I am confused maybe the first line of the code is wrong, here is my code:
$: payload = msg.payload.payload_fields.humidity;
payload_raw: new Buffer(payload).toString('base64'),
Wishing someone can solve my problem. Thanks very much!