It's so confusing ... pin 20..., pin A5... pin D18 ... etc ... Every one uses other names, other numbers ...
Is there any one who can show me a picture or a chart where CLEARLY is stated what pins are what ? (on the Arduino Mega 256)
Thanks in advance.
It's labelled right on the board.
A0 to A15 are also digital 54 to 70.
In your code, do not use Dxx.
byte pinX = 2; // 0 to 69 are valid
byte pinX =A0; // A0 to A15 are valid
You can also google for "arduino mega2560 pinout" and see some pretty good charts.