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Topic: LCD_I2C sometimes works and sometimes doesn't (Read 123 times) previous topic - next topic


I've searched and not find exactly same as my problem.

I use a simple wiring: GND-GND VDD-V5 SCL-SCL SDA-SDA. My code is following. I checked it on a mega and worked. I checked it on an uno which wired to a 4*4 keypad, nothing but white first row was seen. I rechecked it (exactly same condition) on the first board (mega) and just white row. After a while and changing codes, connecting and discontenting all thing, changing board, It worked. I checked it several times, and some times LCD works and sometimes just the white row. What do you think?

Code: [Select]

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd (0x3F, 16, 2);
void setup(){
  lcd.setCursor(0, 0);
  lcd.setCursor(0, 1);
  lcd.print("Check it");
void loop(){


Have you checked the integrity of your connecting wires? 



Mar 16, 2019, 07:23 am Last Edit: Mar 16, 2019, 07:27 am by shimidan
 I checked them several times. I changed them too.
I suspected to integrity of the LCD or its I2C.

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