[SOLVED] 16x2 LCD with ST7066U-0A showing random symbols, the starter kit works

Other Hardware Displays
1

Hi,
I am building a cold wire feeder for my TIG and I finally finished the control panel and decided to test if it's workning. The LCD is connected to a MEGA 2560 board in 4-bit configuration (backlight not connected). When I run my simple code the display shows only full squares, arrows, question marks and asian letters. When I tried it with the LCM1602C, that came with my starter kit, it showed the text just fine. I am new to electronics, so I can't figure out, what's wrong. Thanks in advance.

my test code:

#include <LiquidCrystal.h>

LiquidCrystal lcd(5, 22, 23, 24, 25, 26);

void setup() {

  lcd.begin(16, 2);
  lcd.setCursor(0,0);
  lcd.print("0123456789abcdef");
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print("0123456789ABCDEF");

}

void loop() {
}

}

void loop() {
}

my display datasheet: https://www.tme.eu/Document/1b23b0aab21133389733bd8a09062d9f/DEM%2016214%20FGH-PW.pdf

2

Nevermind, I was desperate so I once again measured it for shorts and there was one in the display data input.

This thread can be safely deleted

3

This thread can be safely deleted

. . . when pigs fly.

Don