Arduino LCD Help!?!

I'm using the Liquid Crystal Library that comes with the arduino software. I am using the "Hello World" code inside this library. Here is the code....

/*

  LiquidCrystal Library - Hello World

Demonstrates the use a 16x2 LCD display.  The LiquidCrystal

library works with all LCD displays that are compatible with the

Hitachi HD44780 driver. There are many of them out there, and you

can usually tell them by the 16-pin interface.

This sketch prints "Hello World!" to the LCD

and shows the time.

  The circuit:

* LCD RS pin to digital pin 12

* LCD Enable pin to digital pin 11

* LCD D4 pin to digital pin 5

* LCD D5 pin to digital pin 4

* LCD D6 pin to digital pin 3

* LCD D7 pin to digital pin 2

* LCD R/W pin to ground

* 10K resistor:

* ends to +5V and ground

* wiper to LCD VO pin (pin 3)

Library originally added 18 Apr 2008

by David A. Mellis

library modified 5 Jul 2009

by Limor Fried (http://www.ladyada.net)

example added 9 Jul 2009

by Tom Igoe

modified 22 Nov 2010

by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/LiquidCrystal

*/

// include the library code:

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {

  // set up the LCD's number of columns and rows:

  lcd.begin(16, 2);

  // Print a message to the LCD.

  lcd.print("hello, world!");

}

void loop() {

  // set the cursor to column 0, line 1

  // (note: line 1 is the second row, since counting begins with 0):

  lcd.setCursor(0, 1);

  // print the number of seconds since reset:

  lcd.print(millis()/1000);

}

Thanks,

Nehemiah

I'm using the Liquid Crystal Library that comes with the arduino software. I am using the "Hello World" code inside this library. Here is the code....

/*

  LiquidCrystal Library - Hello World

Demonstrates the use a 16x2 LCD display.  The LiquidCrystal

library works with all LCD displays that are compatible with the

Hitachi HD44780 driver. There are many of them out there, and you

can usually tell them by the 16-pin interface.

This sketch prints "Hello World!" to the LCD

and shows the time.

  The circuit:

* LCD RS pin to digital pin 12

* LCD Enable pin to digital pin 11

* LCD D4 pin to digital pin 5

* LCD D5 pin to digital pin 4

* LCD D6 pin to digital pin 3

* LCD D7 pin to digital pin 2

* LCD R/W pin to ground

* 10K resistor:

* ends to +5V and ground

* wiper to LCD VO pin (pin 3)

Library originally added 18 Apr 2008

by David A. Mellis

library modified 5 Jul 2009

by Limor Fried (http://www.ladyada.net)

example added 9 Jul 2009

by Tom Igoe

modified 22 Nov 2010

by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/LiquidCrystal

*/

// include the library code:

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {

  // set up the LCD's number of columns and rows:

  lcd.begin(16, 2);

  // Print a message to the LCD.

  lcd.print("hello, world!");

}

void loop() {

  // set the cursor to column 0, line 1

  // (note: line 1 is the second row, since counting begins with 0):

  lcd.setCursor(0, 1);

  // print the number of seconds since reset:

  lcd.print(millis()/1000);

}

Thanks,

Nehemiah

OK, so i set up the same on my display, same wiring, same code

If the variable resistor is not set correctly then you can get the symptoms you describe, measuring the voltage on Vo (Pin 3 of the LCD.. from the left in your diagram), i get a good display at ~1.3v, it will go blocks if the volts are nearer to zero and will go clear if much above that toward 5V

so it is possible that your screen is working and that you need to carefully adjust the contrast, if you can measure the volts on the pin, what are you getting now, and then try to adjust very slowly either way to try get a display

you will need to check your wiring carefully to make sure there are no mistakes, and like I said, check the voltage on the Vo pin, adjusting the pot should make it change between 5V and 0V, you will need it to be about 1.3ish, this may vary between LCD makes but with luck this will solve your problem

I am assuming the Arduino is ok and that you have a good LCD. Your symptom is very much like I get when the adjustment is not correct on Vo.

If this does not fix your issue, take a good quality picture of your wireing and post it, maybe one of the viewers can see an error or suggest something. If you have a second display, i would try that one too

Good luck

peter

Peter is right.  Sounds like the contrast level is not properly adjusted.