Interfacing 16×2 LCD with Pinguino 18F2550

Posted by Pranav Pareek on Jun 25, 2013 in Blog | 1,560 comments

Recently in one of my project I needed to add 16×2 LCD so I tried to use Pinguino LCD library provided in the example folder of the IDE. But for some reason it didn’t worked, so I downloaded HD44780 datasheet and build my own LCD interface program.

demo:

code:

/*
This is a 16×2 LCD display demonstration. 25 Jun 2013
Author: Pranav Pareek (http://www.pranavpareek.com)

Connection as follows:
* VEE = GND
* EN = PORTC.6
* RS = PORTC.7
* RW = PORTB.4
* LCD D4 = PORTB.0
* LCD D5 = PORTB.1
* LCD D6 = PORTB.2
* LCD D7 = PORTB.3
* B/L+ = ICSP Pin 2
* B/L- = ICSP Pin 3

*/

#define EN 8
#define RS 9
#define RW 4
#define LED 12

void lcd_cmd_data(unsigned char cmd, int rs) {
if(rs == 1) {
digitalWrite(RS,HIGH);
}
else {
digitalWrite(RS,LOW);
}
digitalWrite(EN,LOW);
PORTB = ((cmd >> 4) & 0x0F);
digitalWrite(EN,HIGH);
delay(10);
digitalWrite(EN,LOW);
PORTB = (cmd & 0x0F);
digitalWrite(EN,HIGH);
delay(10);
digitalWrite(EN,LOW);
}

void init_lcd() {
digitalWrite(RW,LOW);
digitalWrite(RS,LOW);
digitalWrite(EN,LOW);
PORTB = 0x03;
delay(50);
digitalWrite(EN,HIGH);
digitalWrite(EN,LOW);
delay(10);
digitalWrite(EN,HIGH);
digitalWrite(EN,LOW);
delay(10);
digitalWrite(EN,HIGH);
digitalWrite(EN,LOW);
delay(10);
PORTB = 0x02;
digitalWrite(EN,HIGH);
digitalWrite(EN,LOW);
lcd_cmd_data(0x28, 0);
delay(250);
lcd_cmd_data(0x0E, 0);
delay(250);
lcd_cmd_data(0x01, 0);
delay(250);
lcd_cmd_data(0x06, 0);
delay(250);
lcd_cmd_data(0x80, 0);
delay(250);
}

void puts_lcd(const char * string) {
lcd_cmd_data(0x08, 0);
while(*string) {
lcd_cmd_data(*string++, 1);
}
lcd_cmd_data(0x0E, 0);
}

void pos_xy(int posX, int posY) {
if(posX<40) {
if(posY) {
posX|=0b01000000;
}
posX|=0b10000000;
lcd_cmd_data(posX, 0);
}
}

void setup() {
pinMode(RS,OUTPUT);
pinMode(EN,OUTPUT);
pinMode(RW,OUTPUT);
pinMode(LED,OUTPUT);
init_lcd();
puts_lcd(”  16×2 LCD Demo “);
pos_xy(0,1);
puts_lcd(“PranavPareek.Com”);
}

void loop() {
digitalWrite(LED,HIGH);
delay(250);
digitalWrite(LED,LOW);
delay(250);
}

Parts used above are available here:

16×2 LCD: http://www.anceop.com/?action=page&param=viewProduct&id=68018

Pinguino 18F2550: http://www.anceop.com/?action=page&param=viewProduct&id=16278