Rotary encoder jumps 'in between'

Projects Programming
1

Dear all

First post here and completely new to Arduino and electronics in general :confused:
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 somewhere in between the 'click'.

Did a lot of research on internet, but couldn't find a solution.
Some rotary libraries I found don't work with the Mega.

Do I have to change anything in this part firmware of Makelangelo?
I played a lot (without really knowing what I was doing) with "ENCROT" changing ++ and -- into +20 or -10 and so on. It looked like having some effect, but not good enough and random...

Thx in advance!

int buttons=0;
unsigned long next_lcd_read=0;
const char *update_key;
void *update_val;


void LCD_read() {
  long now = millis(); 
  
  if(ELAPSED(now,next_lcd_read)) {
    // detect potentiometer changes
    buttons = ((digitalRead(BTN_EN1) == HIGH) << BLEN_A) 
            | ((digitalRead(BTN_EN2) == LOW) << BLEN_B); //was HIGH
    next_lcd_read=now+30; 
  }
  
  // potentiometer uses grey code.  Pattern is 0 3 1 2
  if (lcd_rot_old != buttons) {
    switch (buttons) {
      case ENCROT0:  switch( lcd_rot_old ) { case ENCROT3: lcd_turn++; break; case ENCROT1: lcd_turn--; break; } break;
      case ENCROT1:  switch( lcd_rot_old ) { case ENCROT0: lcd_turn++; break; case ENCROT2: lcd_turn--; break; } break;
      case ENCROT2:  switch( lcd_rot_old ) { case ENCROT1: lcd_turn++; break; case ENCROT3: lcd_turn--; break; } break;
      case ENCROT3:  switch( lcd_rot_old ) { case ENCROT2: lcd_turn++; break; case ENCROT0: lcd_turn--; break; } break;
    }
    // for debugging potentiometer
    {
      //if(lcd_turn !=0) Serial.print(lcd_turn>0?'+':'-');
      //else Serial.print(' ');
      //Serial.print(millis());     Serial.print('\t');
      //Serial.print(lcd_rot_old);  Serial.print('\t');
      //Serial.print(buttons);      Serial.print('\t');
      //Serial.print(lcd_turn);     Serial.print('\n');
    }
    
    lcd_rot_old = buttons;
  }

  // find click state
  int btn = digitalRead(BTN_ENC);
  if ( btn != lcd_click_old && btn == HIGH ) { 
    // when button is released
    lcd_click_now = true;
  }
  lcd_click_old = btn;
}
2

On a 3D printer with Marlin firmware it typically requires four encoder steps before taking one step in the menu. Perhaps you can implement something like that.

3

You're reading the encoder every 30 ms, that's way too slow.

Why are you using void pointers?

Pieter

4

johnwasser:
On a 3D printer with Marlin firmware it typically requires four encoder steps before taking one step in the menu. Perhaps you can implement something like that.

I think something like that is needed, but how is a big question for me...

5

PieterP:
You're reading the encoder every 30 ms, that's way too slow.

Why are you using void pointers?

Pieter

I changed that 30 into 1 or even into 1000. No change in anything usefull for me.

I don't use anything :slight_smile: the code is from Makelangelo firmware. The part I posted is what I think responds in tuning the encoder.
Could be wrong!