I2C LCD Library Problem in 2.0.3 Editor

Projects Programming
1

Hi,
I was experimenting with LCD displays using I2C and copied some basic code with the library <LiquidCrystal_I2C.h> I uploaded the code to my uno board and all of a sudden, this error message pops up.

C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\ESC_Ctrls.ino: In function 'void setup()':
C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\ESC_Ctrls.ino:6:6: error: redefinition of 'void setup()'
 void setup()
      ^~~~~
C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\I2c_Adrs_Finder.ino:7:6: note: 'void setup()' previously defined here
 void setup() {
      ^~~~~
C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\ESC_Ctrls.ino: In function 'void loop()':
C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\ESC_Ctrls.ino:19:6: error: redefinition of 'void loop()'
 void loop()
      ^~~~
C:\Users\palla\Documents\Arduino\I2c_Adrs_Finder\I2c_Adrs_Finder.ino:40:6: note: 'void loop()' previously defined here
 void loop() {}
      ^~~~

exit status 1

Compilation error: redefinition of 'void setup()'

Do any of you know what I should do?
Here is my code:

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

LiquidCrystal_I2C lcd(0x27,20,4);  // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup()
{
  lcd.init();                      // initialize the lcd 
  lcd.init();
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(1,0);
  lcd.print("hello everyone");
  lcd.setCursor(1,1);
  lcd.print("This works");
}


void loop()
{
}
2

And

You have 2 .ino file in the same map. Each of them had setup and loop in it. That will not work. Remove setup and loop from ESC_Ctrls.ino

3

Thanks. I have another question. I can't see the text printing. Do you know why this is happening?

4

There could be a number of reasons:

  1. The display is not at address 0x27 (use I2C scanner to verify)
  2. SDA/SCL connections reversed
  3. Contrast setting needs to be adjusted

I also found that the 2004 display struggled when powered from the Arduino 5V rail and contrast was much better when it was powered from an external 5V power supply.

5

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