LCD I2C is not displaying

[zenthon9]

Hi, I'm newbie with arduino and I'm trying to use an I2C with a LCD 16x2. For the moment I'm just trying to make a "Hello World" program, but the LCD only displays white squares on the first row. I've tried with different programs/codes that i've seen on youtube, but there hasn't been any difference.

This is the code that I'm using. If someone can help me, I would really appreciate it

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); 

void setup()
{
  lcd.init();
  lcd.backlight();
}

void loop()
{
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Hello World");
}

And this is what I have

Btw, I'm using the library of Frank de Brabander.

[qubits-us]

Hi @zenthon9 ,

Welcome to the forum..

@zenthon9

using the library of Frank de Brabander.

is it this lib here??

if yes, then strange as there is no lcd.init(), suppose to use lcd.begin()..

good luck.. ~q

[LarryD]

• Check the soldering.
• Back down on the contrast potentiometer.
• Run the I2C scanner sketch to check the address.

[van_der_decken]

Your sketch works with a PCF8574 backpack (though I'd take all the code out of the loop function and put it at the end of the setup function). As well as the things @LarryD mentioned, check your wiring to make sure you've got continuity on the SDA and SCL lines.

If your backpack has a PCF8475A IC, try using address 0x3F rather than 0x27.

[zenthon9]

Good news, the lcd with the I2C is working now. It seems it was the soldering on RW. After I fix it, it is now displaying the hello world message. Thank you all for the help!