IoT Central map gps long/lat format

Hi,
I assuming that you are using Adafruit_GPS library and then you created an object called “GPS to obtain latitudeDegrees and longitudeDegrees which are float type.
So I think that maybe there is still some issue with your JSON
I don’t have Adafruit GPS module but I was able to make some test after modifying your createEventPayload() function

void createEventPayload(int temp, float longi, float lati)
{
  //JsonWriterStatic<256> jw;
  
    char data[] = "{\"temp\":%d,\"gps\":{\"lat\":%f,\"lon\":%f},\"lat\":%f,\"lon\":%f}";
    char finall[sizeof(data) + 32];
    snprintf(finall, sizeof(finall), data, temp, lati, longi, lati, longi);
    
    Particle.publish("Test_data", finall, 60, PRIVATE);
}

I just call the function like this
createEventPayload(32, 52.0764, 54.1765); for testing JSON
but you can do it like this:
createEventPayload(32, GPS.longitudeDegrees, GPS.latitudeDegrees);
and the output looks like one of yours above and is valid JSON format