Behind the scenes, Arduino borrowed heavily from another project called Processing.
Processing was a visual-art-coding platform developed in Java by Ben Fry and Casey Reas, but it has evolved into far more than that today.
The Arduino project used the Processing code as a basis for the Arduino programming environment so it will appear quite familiar as you learn it.
We can use Processing as a tool to talk to Arduino!
Grab the software from processing.org – it’s free.
In this example, we evolve the previous user-input example and will set the color of the RGB using a visual user interface, rather than by inputting text.
We will set the color using sliders, then press a key on the keyboard to send the color to the Arduino over the USB serial.
On the Arduino side we will wait for the color information sent as a comma-delimited list.
To get the correct individual values, we do some tricks on both sides. Look out for those in the code!