I just started with Cayenne so, maybe, I made a mistake.
I am testing on Arduino Uno with W5100 ethernet shield and using Web dashboard
I wished to upload the internal temperature of the Atmega 328 so I loaded the Cayenne Line Chart Widget Example, and modified only a line and added only a function.
I added this line
Cayenne.virtualWrite(VIRTUAL_PIN, GetTemp(), TEMPERATURE, CELSIUS);
GetTemp is the function that return a double.
I added a Serial.print to debug temperatures
The temperatures printed locally are around 28-30 C but in dashboard I see values between 80 and 85.
When I created the widget I specified to use Celsius but my suspect is that the Celsius values are still converted in Fahrenheit.