4x20 LCD Display to work with Freeduino

Forum 2005-2010 (read only) Hardware Troubleshooting
1

Hello all,

I am back with my 4th version of my project, hoping that this time I will attain my targets.

The new system is shown in an attached picture.

As you can see, the led is lit, the LCD Display is active, but only a couple of black squares shows in to lines and there is no backlight.
The image of my project can be seen here:

To check the display and board I used the following sketch:

#include <LiquidCrystal.h>

/* LiquidCrystal display with:
LCD 4 (RS) to arduino pin 12
LCD 5 (R/W) to ground (pin 14)
LCD 6 (E) to arduino pin 11
LCD DB4, DB5, DB6, DB7 on arduino pins 7, 8, 9, 10 */

LiquidCrystal lcd(12, 14, 11, 7, 8, 9, 10);

void setup()
{
  lcd.setCursor(2,0); // Position cursor on line x=3,y=1
  lcd.print("4x20 LCD DISPLAY"); // Print a message to the LCD
  lcd.setCursor(3,1);
  lcd.print("with controller");
  lcd.setCursor(7,2);
  lcd.print("HD44780");
  lcd.setCursor(1,3);
  lcd.print("useful for Arduino");
}

void loop()
{
}

It compiles ok, uploads to the board, but do not show results in the LCD Display.

Hope some of you can help me a little.

Thanks a lot.

OldBeaver

2

A couple of things you can try.

 lcd.begin(20,4);
  lcd.clear();

At the beginning.

And try the 6 pin version by wiring LCD pin 5 to ground and changing

LiquidCrystal lcd(12, 11, 7, 8, 9, 10);
3

Thank you much, for the very fast answer, I will try and tell.

OldBeaver

4

Well,

lcd.begin(20,4); is not accepted by the compiler....

Where should I put it?

OLdBeaver

5

Needs to be inside your Setup().

It should be accepted, but only in your setup I believe, I'm using 0017, and tried on 0016 as well, you do need the lcd.begin to get anything to display. (Using a 4x20 with HD47780)

But I've got to agree with the pin to ground, what that does is always enables WRITE. Pin5 == Read/Write. And since the HD47780 is only WRITE compatible only, no need to try read it. :smiley:

Best of luck!

6

Will check that. Thank you much.

OldBeaver

7

Hello all LCD users!

Now my 4x20 backlit LCD display is working fine!

Look at this picture: BBB w LCD, BUB Programmer & dev board 03 | This is my 4x20 L… | Flickr

Thanks to all that helped me on solving my problems. It was just a matter of correct wiring.

At present I have the following wiring:

LCD Board Freeduino Board
Pin No. Pin No.
1 Vss GND
2 Vdd 5V
3 V0 variable (contrast)
4 RS data 12
5 R/W read/write 14
6 E enable 11
7 data
8 data
9 data
10 data
11 data 7
12 data 8
13 data 9
14 data 10
15 Anode backlit to 3.8 V
16 Cathode backlit to GND

Hope this serves to others.

OldBeaver