ST7920 LCD - Display problem.

I have a graphic display 128x64 with controller ST7920 connected serially to an Arduino Mega 2560. Using the library u8glib. The problem is that looking at the front of the display pixels appear as faded, while slightly tilting the display appear perfectly white. I tried using a potentiometer to adjust the contrast pin v0 but seems to be ignored.

I hope in your help.


What is the exact display type (link)?
How did you wire the var pot (picture)?


Link display:

PWM pin 46 used to control backlight.

The red wire, which goes to the var pot, must be connected to Vout of the Display Module.


Hi Oliver, I connected to pin Vout but still does not work.

Maybe you can update your nice picture for more detailed review.


Contrast works! Enable jumper J1. This is the solution:

Strange. I never heard of such a jumper. Good to know and thanks for keeping us updated.