Rotary encoder jumps 'in between'

Dear all

First post here and completely new to Arduino, reprap and electronics in general :smiley-confuse:
I started making a polargraph / V-plotter.
Bought stepper motors, Arduino Mega 2560, Ramps 1.4, etc... and an LCD.
The LCD is from RepRapDiscount: full graphic smart controller.

After a long search and a big puzzle using Makelangelo software, I got it more or less under control.
Except the rotary encoder on the LCD-panel...
I can only change lines in the menu if I really really really am soft on the knob.
It reacts only somewhere before the 'click'.


Did a lot of research on internet, but couldn't find a solution.
Posted in Dutch part, but no reaction. Arduino forum, no reaction.

Some help please!
Thx in advance!

everything but the information we need... what firmware is running on the mega?

Told you I am a novice
The Mega runs on 1.8.10.
The LCD is working (did graphics test in u8glib and I see the menu from Mikelangelo).

I'm looking forward to give more info...

Oh It runs custom firmware [github.com]

so not a reprap at all.

look in lcd.h find the following line
#define LCD_TURN_PER_MENU (3) // was 5

this changes the number of encoder pulses per menu change. increase the number to make it less sensitive,

Edited 3 time(s). Last edit at 11/24/2019 08:27PM by Dust.

Thx for your reply, time and thinking!

I was suspecting this could effect the encoder so I experimented with that already...
Changing from 1 tot 10: no good.
From 5 up there is no reaction anymore. Around 2 is the least bad option...