Hi I'm new I bought ramps 1.4 and full graphic smart controller when I upload marlin I can see the main screen but I can't control with button. The button works on repiter firmware but don't in marlin. Anyone can help me?

The combinations of RAMPS 1.4 and REPRAP_DISCOUNT_SMART_CONTROLLER and REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER are about the most common and best tested ones. So likely there is no error in Marlin for them.

Likely sources for the error could be:
Random Marlin version.
Solder chips on the boards or adapter causing random errors.
Defect cabes - causiing random errors.
Defect switch - causing random errors.
Defect RAMPS or Mega.
Randomly changed pin or other file.

The issue I have with the same setup is the encoder works in reverse ie increase value is anticlockwise and decrease is clockwise, this feels counter-intuitive.

Hey DjDemonD,
I have exactly the same reversed encoder issue. Bugged the hell out
of me 12 months ago. I solved the problem by stopping using it.

It is easy enough to change the direction.

This might already be solved for you:

[github.com] (Look for the Blue-Marlin post at the end of the thread)

Edited 3 time(s). Last edit at 02/26/2016 10:02AM by Roxy.

Okay so set encoder pulses per step to -1 I'll try this and see if it works, thanks.