Need help with displaying text on a LCD 16x2

Other Hardware Displays
1

Hello everyone,

I'm having trouble getting my 16x2 LCD to display text using my Arduino UNO. Right now, the screen just lights up blue, and absolutely nothing is displayed.

Here’s how I’ve connected the wires:

  • GND from LCD ➔ GND on Arduino
  • VCC from LCD ➔ 5V on Arduino
  • SDA from LCD ➔ A4 on Arduino
  • SCL from LCD ➔ A5 on Arduino

I’ve double-checked my connections, and both the Arduino and the LCD appear to be functioning properly, but I can’t get the LCD to show "Hello World" or anything else.

If anyone has any suggestions or troubleshooting tips, I would greatly appreciate your help!

This is my code:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); 

void setup() {
  lcd.begin(16, 2);
  lcd.backlight(); 
  lcd.setCursor(0, 0);  
  lcd.print("Hello World"); 
}

void loop() {
}
2

Is there a blue pot on the display driver?
If so, you might want to adjust it. That is the contrast control.
Did you run the i2c scanner sketch? Are you certain the address is 0x27?

Edit: I should have seen this right away. Don't use this:
lcd.begin(16, 2);
Use this:
lcd.init();

3

Topic moved !! Please do not post in "Uncategorized"; see the sticky topics in Uncategorized - Arduino Forum.

4

Yes,on the back there is a blue potentiometer ont he back,how do i adjust it?

5

First try the code change. Mine won't work with the lcd.begin() call. It needs lcd.init().

6

it doesnt work with lcd.init()Still shows empty blue screen

7

Are you certain the i2c address is 0x27? i2c_scanner sketch should show that.
If that doesn't work, then adjust the screw on the blue pot with a small screwdriver.

8

i tested,and it is 0,27 address

9

Try adjusting the blue potentiometer.
Are you certain the LCD driver board is connected correctly both ways?
Jumpers connected to the Arduino are correct?
The driver to the display is soldered correctly? Can't be just pushed in.

10

Using the IDE library manager, install the hd44780 library by Bill Perry.

Run the example sketch at File > Examples > hd44780 > ioClass > hd44780_I2Cexp > I2CexpDiag

See what the sketch outputs onto the serial monitor.

11

ill try to adjust the potentiometer

12

Try that.

The driver board is soldered to the display, correct?
Some come separate and expect the user to connect them. They can't just be pushed together. It must be soldered. Just checking.

13

Yes it works,thanks bud

14

You are very welcome! Have fun!