It took me a bit to realize how the constructor parameters worked.
It doesn't seem to be documented and it is reversed/backwards from all the other LCD libraries.
All the other "LiquidCrystal" type libraries have a set of fixed ordered parameters of lcd function that get passed
i/o pin #s.
The argument position of the parameter determines the hd44780 LCD function and the value is the i/o pin number connected to that LCD function pin.
For direct pin control you pass in Arduino pin #s, for output port devices you pass in the port bit number.
This library uses a fixed set of i/o pins that get passed a hd44780 pin # of the hd44780 LCD function it is controlling.
The argument position determines the i/o port bit number in the expansion port, and the value is the hd44780 pin number of that function. The exception being the backlight which is pin 16 - but that i/o port pin is really driving a backlight circuit and not the actual LCD.
It is very different from other libraries. And is worthy of some documentation to explain how it works.
--- bill