LCD 20 X 4 NO TEXT

hello,
this is one of my first try’s with arduino.
I am trying to print a simple text to a LCD display i2c 20 x 4.
But nothing is displaying on the display.
This is the Display i have:

This is the code i found for testing

/*
** Example Arduino sketch for SainSmart I2C LCD Screen 16x2
** based on https://bitbucket.org/celem/sainsmart-i2c-lcd/src/3adf8e0d2443/sainlcdtest.ino
** by
** Edward Comer
** LICENSE: GNU General Public License, version 3 (GPL-3.0)

** This example uses F Malpartida's NewLiquidCrystal library. Obtain from:
** https://bitbucket.org/fmalpartida/new-liquidcrystal 

** Modified - Ian Brennan ianbren at hotmail.com 23-10-2012 to support Tutorial posted to Arduino.cc

** Written for and tested with Arduino 1.0
**
** NOTE: Tested on Arduino Uno whose I2C pins are A4==SDA, A5==SCL

*/
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x3F // <<----- Add your address here.  Find it from I2C Scanner
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

int n = 1;

LiquidCrystal_I2C  lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);

void setup()
{
  lcd.begin (20,4); //  <<----- My LCD was 20x4

  
// Switch on the backlight
lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);
lcd.setBacklight(HIGH);
lcd.home (); // go home

  lcd.print("Hallo");  
}

void loop()
{
  // Backlight on/off every 3 seconds
  lcd.setCursor (0,1);        // go to start of 2nd line
  lcd.print("goodbye");
  lcd.setBacklight(LOW);      // Backlight off
  delay(500);
  lcd.setBacklight(HIGH);     // Backlight on
  delay(10000);
}

I found the I2C_ADDR with the i2c_scanner on the arduino website.
Why does it not work

i2c_03.jpg.png

To post a link you need to use the "Insert a link" button. It looks like you used "Insert an image".

Here's a link to the product page.

Here's an image of the display.

(I used right click > Copy image URL.)

And here's the image you attached.

i2c_03.jpg.png

(I used "Copy link address" and pasted in with the "Insert an image" button. I'm not sure how to insert an image when you upload it yourself.)

Geert75:
This is the code i found for testing

Did you try the code from the product page?

Geert75:
I found the I2C_ADDR with the i2c_scanner on the arduino website.

Geert75:

#define I2C_ADDR    0x3F // <<----- Add your address here.  Find it from I2C Scanner

0x3F is the I2C address? The product page says the default address is 0x20.

I suspect something went wrong when you read the address.

I notice you received a bunch of replies to an earlier post. It doesn't seem very polite to ignore the input you were given.

Hey

hallo DuaneDegn,

the problem is solved, i needed to adjust the brightness of the display.
About the adress, the adress needs to be 0x3F, i tried it with the adress 0x20 and the display freezes.

Geert75:
the problem is solved, i needed to adjust the brightness of the display.

Thanks for reporting back. I know you're not the first one to have that problem.