Communicate with the instrument on serial ========================================= If you plug the measuring instrument on a USB port of your computer, you could communicate together. Certainly not for long palaver; only to ask it for data, and it to send them back to you. But that's pretty much what we expect, right? The communication operates on serial. It's directly possible within the Arduino IDE as well as via a dedicated third-party software such **Minicom**. In the Arduino IDE, just click on the *serial monitor* button to open the communication window. For Minicom, you can use such a command: .. code:: bash minicom -b 9600 -D /dev/ttyUSB0 Where ``/dev/ttyUSB0`` is the used serial port in this example. How to ask for data ------------------- Whatever software is used, once connected it is really easy to ask for data. Just send word ``data`` on serial for the instrument to measure current values and send them back, formatted as follows:: TempSky: 2.77 TempSensor: 35.87 TempAmbient: 28.32 TempDiff: 25.55 Where ``TempSky`` is the sky temperature, ``TempSensor`` the sensor temperature, ``TempAmbient`` the ambient temperature as measured by an independant sensor inside the forced ventilated housing, and ``TempDiff`` the temperature difference between ``TempAmbient`` and ``TempSky``. How to interpret data --------------------- The sky condition can be approximately deduced from the ``TempDiff`` value: - **Overcast** between 0 and 10; - **Cloudy** between 10 and 20; - **Clear** below 20.