LiquidCrystal does not work...

Forum 2005-2010 (read only) Hardware Troubleshooting
1

Everything uploads and compiles... but nothing shows up in the lcd. All the connections seem to be ok but still no letters in the display.

any sugestions... what am i doing wrong???

2

Did you connect a trim pot to the contrast pin? If not, the LCD might be working and you just can't see it.

3

yes I have. I have a normal potentiometer connected to the contrast pin of the lcd and when it is turned the contrast changes: the top line turns all the squares brighter and almost no changes occur in the bottom line.. but still no text..

I am using the following code:

#include <LiquidCrystal.h>

// LiquidCrystal display with:
// rs on pin 12
// rw on pin 11
// enable on pin 10
// d0, d1, d2, d3 on pins 5, 4, 3, 2
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

void setup()
{
// Print a message to the LCD.
lcd.print("hello, world!");
}

void loop()
{
}

and the XIAMEN OCULAR GDM1602K LCD

4

If your going to use 4-bit control, then you need to connect the Arduino to d4-d7 on the LCD, not d0-d3.

5

thanks!!! that was it.....