UDP MQTT to Openplotter with ESP32

[PaddyB]

But I guess it’s a format where I have to state e.g that it’s a temp value and it’s measure in degC, or a wind value in this case, measured in knts.

Signalk works in SI units, so temperature is Deg Kelvin, speed is in M/S, direction is in radians etc. 

No need for node red, send a JSON formatted string to signalk and that's it .

Like this >

{
    "updates": [
        {
            "source": {
                "type": "NMEA0183",
                "sentence": "GLL",
                "label": "OPkplex",
                "talker": "GP"
            },
            "timestamp": "2017-07-26T12:21:15.000Z",
            "values": [
                {
                    "path": "navigation.position",
                    "value": {
                        "longitude": -7.846666666666667,
                        "latitude": 36.9987
                    }
                }
            ]
        }
    ]
}