Arduino LCD not working

Question

I am getting crazy on my first LCD example.
I use an Arduino Uno and I'd like to try the LCD screen with the easiest example: the Hello World LiquidCrystal example.
I connected the pins in the same way as the example above but the LCD first shows 16 "inverted spaces" in first line and nothing in second line.
Here is my code (exactly the same as the example):

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup() {
    lcd.begin(16, 2);
    lcd.print("hello, world!");
 }

void loop() {
    lcd.setCursor(0, 1);
    lcd.print(millis()/1000);
}

Does anyone know something about this issue?

Quadripartite

that's gonna be an issue with the circuit. Try adjusting the contrast, in first place; re-set the AVR, etc. – Timon

About the contrast, I use a potentiometer to adjust it but the output doesn't change. I checked the circuit a lot of time but, unfortunately, it seems perfect :/ – Quadripartite

Answer 1

Check the numbers or the LCD pin controls. Notice that the last two of them light up the backlight, switch them off so you will see the backlight off, if don't -> you got your LCD inverted!

If you see correctly the backlight but not the text make sure correct voltage is running to the letters using a potentiometer (check connections properly)

Hope this helps!

Halitosis

Answer 2

the light and power work fine. After redo the connection of digit. I find that they not properly connected. I suggest do some soldering for better connection. I used pin but they not work properly because no soldering.

Gar

Answer 3

You followed the wrong tutorial, I've done the same thing and also had problems but if you go here and follow this tutorial all the way through it should work fantastically!

The main difference you'll notice is this:

LiquidCrystal lcd(7, 8, 9, 10, 11, 12); 

Bride

Answer 4

The task context is not described. Unknown display model and connected libraries. Most often, the issue is solved by the datasheet, but you did not leave a chance to find the desired datasheet.

Chattel

Answer 5

As I can see you have not included the liquidcrystal library. to do that type:

#include <LiquidCrystal.h>

Baucis