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Topic: HD44780 LCD hookup help. (Read 1 time) previous topic - next topic


Hey all i am in need of some help hooking up my HD44780 20*4 LCD.

I currently have it wired as so on the HD44780:

1    Vss  GND
2    Vcc  5V
3    Vee GND
4    RS   PD4 on AVR
5    RW  GND
6    E     PD5 on AVR
7   DB0  not connected
8   DB1  not connected
9   DB2  not connected
10 DB3  not connected
11 DB4  PD0 on AVR
12 DB5  PD1 on AVR
13 DB6  PD2 on AVR
14 DB7  PD3 on AVR
15 A     +5V with 330[ch937]
16 K           GND

And this is my arduino code:
Code: [Select]

#include <LiquidCrystal.h>

// LiquidCrystal display with:
// rs on pin 4
// rw on pin 11
// enable on pin 5
// d4, d5, d6, d7 on pins 0, 1, 2, 3, 4
LiquidCrystal lcd(4, 11, 5, 0, 1, 2, 3);

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

void loop()

However, nothing shows up on the LCD :(

What could i be doing incorrect? I never connected the rw to the arduino, just to ground.



pins 0 and 1 are used by the serial port, try using different pins


Alright i moved 0 and 1 to 6 and 7 but still nothing..
Code: [Select]

LiquidCrystal lcd(4, 11, 5, 6, 7, 2, 3);




Ok, i got it working. I must of had a wire crossed..

Thanks for your help, mem.



As  a side note, I believe the data pins are supposed to be a set of 4 sequential pins (because of "Lazy coding").  Personally, I use the LCD4Bit library since it doesn't require the RW pin and had a couple of new fun and usable functions like scrolling.  Glad you got it working though.
Whats a warranty?


I believe the data pins are supposed to be a set of 4 sequential pins (because of "Lazy coding").

The 'lazy coding' is actually in the lcd4bit library. LiquidCrystal has no such requirement


I was going to use that but all it displayed was Japanese-type on the lcd so i just used the example one that came with arduino software. Not sure what happened, i changed all the values in the c++ file to what worked for the arduino example code...


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