LCD

Forum 2005-2010 (read only) Hardware Interfacing
1

LCD is not working :(. I have GDM1601E.

/*
  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
 * 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 ()
 example added 9 Jul 2009
 by Tom Igoe
 modified 8 Feb 2010
 by Tom Igoe
 
 This example code is in the public domain.

 */

// 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, 1);
  // 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);
}
2

What isn't working? What have you tried. How did you wire the LCD?

3

No result on screen. Like it's off. I wired as shown in code.

4

No change. I will try now to reconnect all wires. Why is here:

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

and here:

LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

??

5

Dario:

Have you dealt with the R/W line properly?

In this case: LiquidCrystal lcd(12, 11, 5, 4, 3, 2); it must be connected to GND.

In this case: LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2); it must be connected to pin 11.

Don

6

I just got it. Few hours ago. I don't believe that I got broken LCD. I tried again wiring it and I'm not very sure how to count pins. Which pin is marked as 1?

7

Which pin is marked as 1?

There's no legally-enforced standard, so it's always best to try to find a datasheet.

There is an industry standard that's mostly followed of making the pad for pin 1 on a connector square/rectangular rather than round/oval.

8

I just got it.

Does this mean that it is working now?

Which pin is marked as 1?

(1) Search Google for 'GDM1601E'
(2) Click on the first hit and download the datasheet
(3) Look at the picture on the first page

OR

Look at your LCD module itself. I'd be surprised if pin 1 wasn't marked on the silk screen.

Don

9

I got wiring now. LCD is not working. Can I somehow connect him to use all 8 data bus?

10

It's time to start all over. Remove all of the wires and then follow the tutorial at http://www.ladyada.net/learn/lcd/charlcd.htm step by step. About half way through there is a photo showing a single line of rectangles - that display is upside down, it's the top row that has the rectangles. If you don't see the rectangles then there is no sense in proceeding any further.

Don

11

I have been trying to compile some code, this may be a simple problem but it is very much annoying me. The compiler does not want to accept this line:

LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2);

every other person I have seen who has been using the LiquidCrystal library uses this line to set the interface pins, it is in every example I have seen. The error message it gives me is

'LiquidCrystal' does not name a type.

12

That section of code includes the following lines:

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

I followed what was in the examples that I have seen... and it didnt report any errors about that line[#include.....] , and that is the first line of code in the sketch.

13

It seems to be working now... I noticed that a comment that I wrote like 7 lines down [that had nothing to do with this function, at least it would seem] that went on past the end of the line and didnt get commented out. It seems to have cleared up...