1. itoa(rgbLed.redMappedValue,str,10);
or
2. String(rgbLed.redMappedValue).c_str();
client.publish("OsoyooDataF", str);
line 1 gives me 255 which is the range of the RGB LED from the setup;
analogWriteRange(255);
Line 2 gives me a blank field, still encouraging though because we are at least publishing something....
still tinkering with this, but logging out for now, can you offer me any more hint s?