Rotary Encoder Not Working with ST7920 LCD

Other Hardware Displays
1

On it's own, the rotary encoder works. However when I try to pair it with the LCD, it doesn't seem to function. Nothing prints and I have no idea why. Any ideas?

Rotary Encoder Code:

#include <Encoder.h>
Encoder myEnc(4, 3);

long oldPos = -999;
int rotaryPos;
int pos;

int mod(int dividend, int divisor) {
  return dividend < 0 ? ((dividend + 1) % divisor) + divisor - 1 : dividend % divisor;
}

double increment(double inc) {
  return 4 / inc;
}

void setup() {

  Serial.begin(9600);


}

void loop() {
  long newPos = myEnc.read();

  if (oldPos != newPos && newPos % 4 == 0) {  
    oldPos = newPos;
    pos = newPos;

    //pos = pos / 4;
    rotaryPos = pos / increment(1);
    Serial.println(mod(rotaryPos, 4));
  }
}

Rotary Encoder paired with LCD:

#include <Arduino.h>
#include <U8g2lib.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

#include <Encoder.h>

U8G2_ST7920_128X64_1_SW_SPI u8g2(U8G2_R0, /* clock=*/13, /* data=*/11, /* CS=*/10, /* reset=*/8);

Encoder myEnc(4, 3);

long oldPos = -999;
int rotaryPos;
int pos;

int mod(int dividend, int divisor) {
  return dividend < 0 ? ((dividend + 1) % divisor) + divisor - 1 : dividend % divisor;
}

double increment(double inc) {
  return 4 / inc;
}



void drawButton(int x, int y, int width, int height, int radius, bool highlight) {
  if (highlight == true) {
    u8g2.drawRFrame(x, y, width, height, radius);
  }
}
void setup() {
  
  Serial.begin(9600);
  u8g2.begin();

  u8g2.drawFrame(0, 0, 128, 64);
}

void loop() {
  // put your main code here, to run repeatedly
  u8g2.firstPage();
  do {
    drawButton(10, 3, 108, 13, 5, rotaryPos == 0 ? true : false);
    u8g2.setFont(u8g2_font_6x10_tf);
    u8g2.drawStr(20, 13, "PLACE HOLDER");

    drawButton(10, 18, 108, 13, 5, true);
    u8g2.setFont(u8g2_font_6x10_tf);
    u8g2.drawStr(25, 28, "Turkish March");

    drawButton(10, 33, 108, 13, 5, true);
    u8g2.setFont(u8g2_font_6x10_tf);
    u8g2.drawStr(38, 43, "Fur Elise");

    drawButton(10, 48, 108, 13, 5, true);
    u8g2.setFont(u8g2_font_6x10_tf);
    u8g2.drawStr(26, 58, "Amazing Grace");


   

  } while (u8g2.nextPage());

   long newPos = myEnc.read();

    if (oldPos != newPos && newPos % 4 == 0) {
      oldPos = newPos;
      pos = newPos;

      //pos = pos / 4;
      rotaryPos = pos / increment(1);
      Serial.println(mod(rotaryPos, 4));
    }
}

I've tried movie the rotary encoder code inside and outside of the do...while loop, but nothing happens. Any ideas?

2

Your loop function in the encoder only version, does things that the loop function doesn't do in the combined code.

This is why you are not reading anything when the encoder is moved.

3

Thanks for your help, it's fixed now!

Thanks a lot!