Hi there,
Recently I got my Arduino board (which I am using on a mac) and I was wondering if anybody managed to hook up and LCD using 4 instead of 8 bits..and if so, if that person is willing to share this with me,
KR,
Tjerk Timan
Hi there,
Recently I got my Arduino board (which I am using on a mac) and I was wondering if anybody managed to hook up and LCD using 4 instead of 8 bits..and if so, if that person is willing to share this with me,
KR,
Tjerk Timan
Hi Tjerk.
I didn't tried but i suppose you send info to the lcd in 2 salves, the 4 left's bits and the fourth's right's bits.
i suppose you have to add a delay between the 2 "salves".
if you try it, give us feedback...
i don't find any tuto to communicate to lcd in 4bits, only instructions in the lcd's datasheets.
regards
eric
Here is some code
I didn't test it... please try it out
if it works then write a nice article in the playground and document it
massimo
/*
* LCD 4bit interface example
* 2006 Massimo Banzi
* Based on code written by Craig Lee 1998
*
*/
#define LCD_RS 8 // Register select
#define LCD_EN 9 // Enable
#define LCD_D4 10 // Data bits
#define LCD_D5 11 // Data bits
#define LCD_D6 12 // Data bits
#define LCD_D7 13 // Data bits
void lcd_strobe()
{
digitalWrite(LCD_EN,HIGH);
digitalWrite(LCD_EN,LOW);
}
/* write a byte to the LCD in 4 bit mode */
void lcd_write(byte c)
{
if(c & 0x80) digitalWrite(LCD_D7,HIGH); else digitalWrite(LCD_D7,LOW);
if(c & 0x40) digitalWrite(LCD_D6,HIGH); else digitalWrite(LCD_D6,LOW);
if(c & 0x20) digitalWrite(LCD_D5,HIGH); else digitalWrite(LCD_D5,LOW);
if(c & 0x10) digitalWrite(LCD_D4,HIGH); else digitalWrite(LCD_D4,LOW);
lcd_strobe();
if(c & 0x08) digitalWrite(LCD_D7,HIGH); else digitalWrite(LCD_D7,LOW);
if(c & 0x04) digitalWrite(LCD_D6,HIGH); else digitalWrite(LCD_D6,LOW);
if(c & 0x02) digitalWrite(LCD_D5,HIGH); else digitalWrite(LCD_D5,LOW);
if(c & 0x01) digitalWrite(LCD_D4,HIGH); else digitalWrite(LCD_D4,LOW);
lcd_strobe();
delayMicroseconds(40);
}
/*
* Clear and home the LCD
*/
void
lcd_clear(void)
{
digitalWrite(LCD_RS,LOW);
lcd_write(0x1);
delay(2);
}
/* write a string of chars to the LCD */
void
lcd_puts(const char * s)
{
digitalWrite(LCD_RS,HIGH); // write characters
while(*s) lcd_write(*s++);
}
/* write one character to the LCD */
void
lcd_putch(byte c)
{
digitalWrite(LCD_RS,HIGH); // write characters
lcd_write(c);
}
/*
* Go to the specified position
*/
void
lcd_goto(byte pos)
{
digitalWrite(LCD_RS,0);
lcd_write(0x80 + pos);
}
/* initialise the LCD - put into 4 bit mode */
void
lcd_init(void)
{
pinMode(LCD_D7,OUTPUT);
pinMode(LCD_D6,OUTPUT);
pinMode(LCD_D5,OUTPUT);
pinMode(LCD_D4,OUTPUT);
pinMode(LCD_EN,OUTPUT);
pinMode(LCD_RS,OUTPUT);
digitalWrite(LCD_RS, LOW); // write control bytes
delay(15);// power on delay
digitalWrite(LCD_D4, HIGH); // init!
digitalWrite(LCD_D5, HIGH); //
lcd_strobe();
delay(5);
lcd_strobe();// init!
delayMicroseconds(100);
lcd_strobe();// init!
delay(5);
digitalWrite(LCD_D4, LOW); // set 4 bit mode
lcd_strobe();
delayMicroseconds(40);
lcd_write(0x28);// 4 bit mode, 1/16 duty, 5x8 font, 2lines
lcd_write(0x0C);// display on
lcd_write(0x06);// entry mode advance cursor
lcd_write(0x01);// clear display and reset cursor
}
void setup() {
lcd_init();
}
void loop() {
lcd_puts("hello world");
}
Dear MAssimo,
Thanx for the effort! I'll work on it today and will definitely post the result!
kr
tjerk
hej,
here is a codeexample for an lcd-display with 4 datapins, if you want i have also a nice pdf with some pictures, schematics and so on ....
tomek
/* LCD display with 4 DataPins
* --------
*
* This is a example in how to use an LCD screen
* configured with data transfers over 2 x 4 bits. The example
* based on the "LCD Hola example" by DojoDave.
*
* There are the following pins to be considered:
*
* - DI, RW, DB0..DB3, Enable (7 in total)
*
* the pinout for LCD displays is standard and there is plenty
* of documentation to be found on the internet.
*
* (cleft) 2006 Tomek for K3 and fh-potsdam
*
*/
int led = 13;
int DI = 12;
int RW = 11;
int DB[] = { 7, 8, 9, 10};
int Enable = 6;
int count = 0;
void LcdCommandWrite(int value) {
int i = 0;
int value1 = 0;
value1 = value;
value1 >>= 4; //send the first 4 databits (from 8) + RW and DI
for (i=DB[0]; i <= DI; i++) {
digitalWrite(i,value1 & 01);
value1 >>= 1;
}
digitalWrite(Enable,LOW); // send a pulse to enable
delayMicroseconds(1);
digitalWrite(Enable,HIGH);
delayMicroseconds(1);
digitalWrite(Enable,LOW);
delayMicroseconds(1); // pause 1 ms according to datasheet
delay(1);
for (i=DB[0]; i <= DB[3]; i++) { // secound part of the secound 4 bits (from 8)
digitalWrite(i,value & 01);
value >>= 1;
}
value >>= 4; // send the RW and DI of the secound 4 bits(from 8)
for (i=RW; i <= DI; i++) {
digitalWrite(i,value & 01);
value >>= 1;
}
digitalWrite(Enable,LOW); // send a pulse to enable
delayMicroseconds(1);
digitalWrite(Enable,HIGH);
delayMicroseconds(1);
digitalWrite(Enable,LOW);
delayMicroseconds(1); // pause 1 ms according to datasheet
}
void LcdDataWrite(int value) {
int i = 0;
int value1 = 0;
digitalWrite(DI, HIGH);
digitalWrite(RW, LOW);
value1 =value;
value1 >>= 4; //send the first 4 databits (from 8)
for (i=DB[0]; i <= DB[3]; i++) {
digitalWrite(i,value1 & 01);
value1 >>= 1;
}
digitalWrite(Enable,LOW); // send a pulse to enable
delayMicroseconds(1);
digitalWrite(Enable,HIGH);
delayMicroseconds(1);
digitalWrite(Enable,LOW);
delayMicroseconds(1); // pause 1 ms according to datasheet
delay(1);
digitalWrite(DI, HIGH);
digitalWrite(RW, LOW);
for (i=DB[0]; i <= DB[3]; i++) {
digitalWrite(i,value & 01);
value >>= 1;
}
digitalWrite(Enable,LOW); // send a pulse to enable
delayMicroseconds(1);
digitalWrite(Enable,HIGH);
delayMicroseconds(1);
digitalWrite(Enable,LOW);
delayMicroseconds(1); // pause 1 ms according to datasheet
}
// this funktion help us to write number over 9, easyely in the lcd display
void LcdNumberWrite(int nr) {
int n1 = 0;
int n2 = 0;
n1 = n2 = nr;
n1 = n1 / 100;
LcdCommandWrite(560 + n1); //512 used to wirte data (see commands for character modul)
n2 = (n2 - n1 * 100) / 10;
LcdCommandWrite(560 + n2); //512 used to wirte data (see commands for character modul)
nr = nr - n1 *100 - n2 * 10;
LcdCommandWrite(560 + nr); //512 used to wirte data (see commands for character modul)
}
void setup (void) {
int i = 0;
for (i=Enable; i <= DI; i++) {
pinMode(i,OUTPUT);
}
delay(100);
// initiatize lcd after a short pause
// needed by the LCDs controller
////////////////////////////// 4 pin initialization
LcdCommandWrite(0x03); // function set:
// 4 pin initialization
delay(64);
LcdCommandWrite(0x03); // function set:
// 4 pin initialization
delay(50);
LcdCommandWrite(0x03); // function set:
// 4 pin initialization
delay(50);
LcdCommandWrite(0x02); // function set:
// 4 pin initialization
delay(50);
LcdCommandWrite(0x2C); // function set:
// 4-bit interface, 1 display lines, 5x7 font
///////////////////////////////////////////////////// end of 4 pin initialization
delay(20);
LcdCommandWrite(0x06); // entry mode set:
// increment automatically, no display shift
delay(20);
LcdCommandWrite(0x0E); // display control:
// turn display on, cursor on, no blinking
delay(20);
LcdCommandWrite(0x01); // clear display, set cursor position to zero
delay(100);
LcdCommandWrite(0x80); // display control:
delay(20);
//////// unter this line are the special stuff you don't need for a initialitzation
LcdCommandWrite(0x0F); // cursor blink
delay(10);
}
void loop (void) {
//>>>>>>>>>>>>>>possible commands for the Lcd Display>>>>>>><< able to use for LcdDisplays with 4 or with 8 DataPins
//LcdCommandWrite(0x01); // clear display, set the cursor to home position
//LcdCommandWrite(0x02); // set cursor position to zero
//LcdCommandWrite(0x0A); // set the display off
//LcdCommandWrite(0x0E); // set the display on and with out cursor blink
//LcdCommandWrite(0x0F); // set the display on and with cursor blink
//LcdCommandWrite(0x0F); // cursor blink
//LcdCommandWrite(0x0E); // cursor not blink
//LcdCommandWrite(0x18); // shift display and cursor to the left
//LcdCommandWrite(0x1c); // shift display and cursor to the right
//LcdCommandWrite(0x14); // shift cursor to the right
//LcdCommandWrite(0x10); // shift cursor to the left
//>>>>>>>>>>>>>>>>>>>>>> example <<<<<<<<<
LcdCommandWrite(0x02); // set cursor position to zero
delay(10);
// Write the message
//like this
LcdDataWrite('L');
LcdDataWrite('c');
LcdDataWrite('d');
//or like this
for ( count = 0; count<=7; count++) {
int wrote [] = { 'D', 'i', 's', 'p', 'l', 'a', 'y', ' ', 'w', 'i', 't', 'h',' ' };
LcdDataWrite(wrote[count]);
}
// and Number over 9 easyely like this
LcdNumberWrite(4);
LcdDataWrite('P');
LcdDataWrite('i');
LcdDataWrite('n');
LcdDataWrite('s');
delay(3000);
}
thanks tomek,
i'll try it next week.
regards
eric
hey tomek,
sounds great! why don't you post it into the www.arduino.cc/playground wiki??
that could help everybody!
thanks in advance
b.
beltran...
i'm enable to login to playground...
would you remove my account ?
i'll try to register an other one
regards
eric
voilà!
you have been deleted!
you and all others can subscribe at the following page
http://www.arduino.cc/playground/Main/LoginForm
there are many contributors but very little content...this thing needs to get working
cheers
b.