help with I2C LCD display

Projects Programming
1

I have just received my 20x4 I2C lcd displays and trying to get some example codes to work but having problems when compiling the examples.
I have downloaded some examples to try my displays but they will not compile for various reasons. A couple have the #include <LCD.h> and i get error message :-
Arduino: 1.6.7 (Windows 7), Board: "Arduino/Genuino Uno"

In file included from C:\Users\Tony\Google Drive\Arduino\lcd_i2c_test\i2c_test_3\i2c_test_3.ino:2:0:

C:\Program Files (x86)\Arduino\libraries\LCD/LCD.h:21:60: fatal error: lcd_config.h: No such file or directory

#include "lcd_config.h" // pin and power configuration file

^

compilation terminated.

exit status 1
Error compiling.

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Do i have something wrong in my library file ?
any help would be appreciated.
The code i am trying to run is;-

[code]
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>  // F Malpartida's NewLiquidCrystal library


#define I2C_ADDR    0x20  // Define I2C Address for controller
#define BACKLIGHT_PIN  7
#define En_pin  4
#define Rw_pin  5
#define Rs_pin  6
#define D4_pin  0
#define D5_pin  1
#define D6_pin  2
#define D7_pin  3

#define  LED_OFF  0
#define  LED_ON  1
LiquidCrystal_I2C  lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);

void setup() 
{
  lcd.begin (16,2);  // initialize the lcd
// Switch on the backlight
  lcd.setBacklightPin(BACKLIGHT_PIN,NEGATIVE);
  lcd.setBacklight(LED_ON);
}

void loop()  
{

// Reset the display 
  lcd.clear();
  delay(1000);
  lcd.home();
 
// Print on the LCD
  lcd.backlight();  
  lcd.setCursor(0,0); 
  lcd.print("Hello, world!");
  delay(8000);
}

[/code]

2

hi,

i also use the LiquidCrystal_I2C.h library.

and this code work great for me.

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3f, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // new lcd = -0x3f old one = 0x27

void setup(){
  lcd.begin(20,4);
  lcd.backlight();
}

void loop(){
lcd.setCursor(0,0);
lcd.print("Hello! world!");
}

only thing you can see is i use I2C address 0x3f or 0x27.
but this can be found with a library that search for pressent I2C devices.

3

Hi thanks for the reply i have just found the examples in the LiquidCrystal_I2C.h library and can confirm that they all compile ok, but none of these use the LCD.h which seems to be included in most of the other examples i found which seems weird so maybe i just stick to the examples shown with the library.

4

wijnendael:
I have just received my 20x4 I2C lcd displays and trying to get some example codes to work but having problems when compiling the examples.
I have downloaded some examples to try my displays but they will not compile for various reasons. A couple have the #include <LCD.h> and i get error message :-
Arduino: 1.6.7 (Windows 7), Board: "Arduino/Genuino Uno"

In file included from C:\Users\Tony\Google Drive\Arduino\lcd_i2c_test\i2c_test_3\i2c_test_3.ino:2:0:

C:\Program Files (x86)\Arduino\libraries\LCD/LCD.h:21:60: fatal error: lcd_config.h: No such file or directory

#include "lcd_config.h" // pin and power configuration file

^

compilation terminated.

exit status 1
Error compiling.

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Do i have something wrong in my library file ?
any help would be appreciated.
The code i am trying to run is;-

[code]

#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>  // F Malpartida's NewLiquidCrystal library

#define I2C_ADDR    0x20  // Define I2C Address for controller
#define BACKLIGHT_PIN  7
#define En_pin  4
#define Rw_pin  5
#define Rs_pin  6
#define D4_pin  0
#define D5_pin  1
#define D6_pin  2
#define D7_pin  3

#define  LED_OFF  0
#define  LED_ON  1
LiquidCrystal_I2C  lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);

void setup()
{
  lcd.begin (16,2);  // initialize the lcd
// Switch on the backlight
  lcd.setBacklightPin(BACKLIGHT_PIN,NEGATIVE);
  lcd.setBacklight(LED_ON);
}

void loop() 
{

// Reset the display
  lcd.clear();
  delay(1000);
  lcd.home();

// Print on the LCD
  lcd.backlight(); 
  lcd.setCursor(0,0);
  lcd.print("Hello, world!");
  delay(8000);
}


[/code]

This LCD.h "library" was designed for this device

Arduino library for LCD screen Matrix Orbital GLK24064-25

( taken from Github source file )

and you actually need the generic one for I2C.

When in doubt always look for source file to identify function of the header file you have #include(d) in your program.

In this case your are actually missing another header file, but you do not need the LCD.h, so toss it.