[BUG] LiquidCrystal ?

Forum 2005-2010 (read only) Hardware Bugs & Suggestions
1

Hi together,

i am working on a projekt. I will connect three LCD 4x20 to Arduino Mega on 4 bit.

One is no Problem, but when i try to connect the secound display i cannot init it.

The first is running perfekt, but the secound makes nothing.

Can someone help me ?

#include <LiquidCrystal.h>

LiquidCrystal lcd_1(22, 23, 24, 25, 26, 27); // the first object runs
LiquidCrystal lcd_2(28, 29, 30, 31, 32, 33); // the secound object dont run.



void setup()
{
  lcd_2.begin(4,20);
  lcd_2.print("Hallo");
  lcd_1.begin(4,20);
  lcd_1.print("Hallo");
  //lcd_2.begin(4,20);
  //lcd_2.print("Hallo");
  
  
  analogWrite(2,225); // Backlight
  analogWrite(3,190); // Kontrast  
}

  
void loop(){
}

Thanks :-)``

2

Try some SetCursor, perhaps...

3

ok, that do not work.
But it is not the code, it is the power suply.

The display are to hungry :wink:

4

Did you check contrast?
I did that the other day without problem but the two screens had different contrast defaults.