I have 2 questions:
a) in the pins definition LiquidCrystal(rs, enable, d4, d5, d6, d7) can I select any pin I like, or some must be PWM pins?
b) I have lcd 20x4. Is there any new apdated library for this type lcd?
Thanks.
You can use any Digital I/O pins you want, including A0 through A5. You can't use A6 or A7 on the devices that support those.
You specify the size in lcd.begin(20, 4).