What exactly does this line of code do: Rotary rotary = Rotary(2, 3);

Projects Programming
1

I have an Arduino running everything as it should. The code drives a stepper motor and follows input from a rotary encoder. The code id from the Buxtronics/GitHub site and seems to work very well.

However, I'm new to Arduino and the coding language. There is a line that I don't understand exactly what it does. It is in the setup and seems to be defining pins 2,3 of the Arduino as encoder input:

// Rotary encoder is wired with the common to ground and the two
// outputs to pins 2 and 3.
Rotary rotary = Rotary(2, 3);

enum PinAssignments {
  encoderPinA = 2,    // right
  encoderPinB = 3,    // left
  clearButton = 5,    // Encoder swtich

It isn't clear to me why the word rotary is repeated twice, once with a capital "R." I tried a number of searches on this, but I don't know what to search for, ie: structures, setup, defines, etc. Can someone tell me what I should be looking at?

Thanks

Dennis

2

Rotary with capital R is a class; rotary with lower case r is a variable of type Rotary (or better phrased, an instance of class Rotary)

3

Thank you so much. At least now I know what to go search for, Class.

Dennis

4 
Rotary rotary = Rotary(2, 3);

Is a lot like:

 int Int = (int)3;

Except that "int" is a built-in type, while "Rotary" is a library-defined type ("Class" - more than a type, but quite similar.)
Since C++ is case-sensitive, "Rotary" (defined by the library) and "rotary" is just a user-provided variable name that could be anything.