How to controle LCD widh Pic 16f877
The most commonly used Character based LCDs are based on Hitachi's HD44780 controller or other which are compatible with HD44580. In this tutorial, we will discuss about character based LCDs, their interfacing with various microcontrollers, various interfaces (8-bit/4-bit), programming, special stuff and tricks you can do with these simple looking LCDs which can give a new look to your application.
For Specs and technical information HD44780 controlle
The most commonly used LCDs found in the market today are 1 Line, 2 Line or 4 Line LCDs which have only 1 controller and support at most of 80 charachers, whereas LCDs supporting more than 80 characters make use of 2 HD44780 controllers.
Most LCDs with 1 controller has 14 Pins and LCDs with 2 controller has 16 Pins (two pins are extra in both for back-light LED connections). Pin description is shown in the table below
| Pin No. | Name | Description |
|---|
| 1 | D7 | Data bus line 7 (MSB) |
| 2 | D6 | Data bus line 6 |
| 3 | D5 | Data bus line 5 |
| 4 | D4 | Data bus line 4 |
| 5 | D3 | Data bus line 3 |
| 6 | D2 | Data bus line 2 |
| 7 | D1 | Data bus line 1 |
| 8 | D0 | Data bus line 0 (LSB) |
| 9 | EN1 | Enable signal for row 0 and 1 (1stcontroller) |
| 10 | R/W | 0 = Write to LCD module
1 = Read from LCD module |
| 11 | RS | 0 = Instruction input
1 = Data input |
| 12 | VEE | Contrast adjust |
| 13 | VSS | Power supply (GND) |
| 14 | VCC | Power supply (+5V) |
| 15 | EN2 | Enable signal for row 2 and 3 (2ndcontroller) |
| 16 | NC | Not Connected |
| Table 2: Character LCD pins with 2 Controller |
simulation :
programmation :
#include <16F877.h>
#device adc=10
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#include "LCD.c"
#define LCD_ENABLE_PIN PIN_B0 ////
#define LCD_RS_PIN PIN_B1 ////
#define LCD_RW_PIN PIN_B2 ////
#define LCD_DATA4 PIN_B4 ////
#define LCD_DATA5 PIN_B5 ////
#define LCD_DATA6 PIN_B6 ////
#define LCD_DATA7 PIN_B7
void main() {
lcd_init();
while(1){ // boucle infinie
lcd_gotoxy(1,1);
printf(lcd_putc,"Smart_Tech Naim"); //Ecrire sur l'ecran lcd
lcd_gotoxy(1,2);
printf(lcd_putc,"smart-tech-med-naim");
}
}
