UDP MQTT to Openplotter with ESP32

[Peter—]

Ok I'm stuck.

Here is my code:

Code:

#include "WiFi.h"
#include "AsyncUDP.h"

const char * ssid = "hidden";
const char * password = "hidden";

AsyncUDP udp;

void setup()
{
   Serial.begin(115200);
   WiFi.mode(WIFI_STA);
   WiFi.begin(ssid, password);
   if (WiFi.waitForConnectResult() != WL_CONNECTED) {
       Serial.println("WiFi Failed");
       while(1) {
           delay(1000);
       }
   }
   if(udp.connect(IPAddress(10,10,10,1), 3333)) {
       Serial.println("UDP connected");
       udp.onPacket([](AsyncUDPPacket packet) {
           Serial.print("UDP Packet Type: ");
           Serial.print(packet.isBroadcast()?"Broadcast":packet.isMulticast()?"Multicast":"Unicast");
           Serial.print(", From: ");
           Serial.print(packet.remoteIP());
           Serial.print(":");
           Serial.print(packet.remotePort());
           Serial.print(", To: ");
           Serial.print(packet.localIP());
           Serial.print(":");
           Serial.print(packet.localPort());
           Serial.print(", Length: ");
           Serial.print(packet.length());
           Serial.print(", Data: ");
           Serial.write(packet.data(), packet.length());
           Serial.println();
           //reply to the client
           packet.printf("Got %u bytes of data", packet.length());
       });
       //Send unicast
       udp.print("Hello Server!");
   }
}

void loop()
{
   delay(1000);
   //Send broadcast on port 3333
//    udp.broadcastTo("this is now working", 3333);
   Serial.println("Sending packages....    ");
   Serial.println(millis()/1000);
//    udp.print("$INMTW,17.9,C*1B");

 udp.print("{\"updates\":[{\"source\":{");
 udp.print("\"values\":[{\"path\":\"environment.outside.temperature\",\"value\":");
 udp.print(millis()/1000);
 udp.print("}]}}]}");
}

On my PI, I can use netcat on the 3333 port and see the JSON-DELTA UDP sentence, so I know it transmitting and recieving. If I copy the netcat output into the SignalK datafiddler it is valid, so I know the format is correct. I have added the connection in SignalK as a Signalk connection on port 3333 with "no self mapping" and logging disabled. When I look in the SignalK diagnose tool there is no temperature readings. What am I missing?

Kind Regards,
Peter