LCD I2C does not work

Other Hardware Displays
1

Hello,
I connected this LCD with SCL,SDA,VSS,GND

to this Arduino R3

at SCL,SDA,5V,GND

and used this library

with the example there:

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

// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
 // initialize the LCD
 lcd.begin();

 // Turn on the blacklight and print a message.
 lcd.backlight();
 lcd.print("Hello, world!");
}

void loop()
{
 // Do nothing here...
}

without success.
Thank you for any help available.

LCD.jpg

UnoR3.jpg
UnoR3.jpg640×531 59.1 KB

2

Does the backlight work? If so, try rotating the trimpot on the I2C interface clockwise to increase the contrast of the display.

3

Hello,
yes, backlight works, if i shortcut the 2 pins at LED

But I guessed the problem is the upload.
I changed the old IDE 1.6.9 to new 1.8.21.0 win10 app.
Before I selected the board Duemilanove without any errors.
Now selecting this board gives upload error.

Thank you

4

Use the hd44780 library. It is in the library manager.
Use the hd44780_I2Cexp i/o class.
First run I2CexpDiag sketch to test i2c signals, backpack and lcd.
Documentation is available in the library and on the github page: GitHub - duinoWitchery/hd44780: Extensible hd44780 LCD library

--- bill

5

Tried sometimes changing ports and boards and uploaded again properly.
LED blinking red and green sometimes, but still thinking LCD still not working.

Turned the poti and all is good.
Great, thank you very much