Hola a todos:
Tengo una LCD de 2x16. La quiero integrar en un proyecto pero no me funciona. Lo que ocurre es que no me muestra nada por pantalla.
Para la LCD utilizo el codigo de Redraven pero modificada para utilizar el Max3003.
Os adjunto dos imagenes con las partes del esquemático que intervienen en la LCD.
El codigo es el siguiente:
MAIN.C:
#include "main.h"
#define EN_AB PIN_D0
//#define LCD_WRITE 0x00
//#define LCD_READ 0xF0
#define LCD_DB4 PIN_D4
#define LCD_DB5 PIN_D5
#define LCD_DB6 PIN_D6
#define LCD_DB7 PIN_D7
#define LCD_E PIN_D1
#define LCD_RS PIN_D3
#define LCD_RW PIN_D2
#include "LCD.C"
void main()
{
setup_adc_ports(NO_ANALOGS|VSS_VDD);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(FALSE);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
setup_oscillator(False);
set_tris_D(0x00);
lcd_init();
lcd_gotoxy(1,1);
lcd_putc('A');
delay_ms(100);
}
LCD.C:
// flex_lcd_2.c
//#define LCD_DB4 PIN_B4
//#define LCD_DB5 PIN_B5
//#define LCD_DB6 PIN_B6
//#define LCD_DB7 PIN_B7
//
//#define LCD_RS PIN_C0
//#define LCD_RW PIN_C1
//#define LCD_E PIN_C2
// If you only want a 6-pin interface to your LCD, then
// connect the R/W pin on the LCD to ground, and comment
// out the following line.
//#define USE_LCD_RW 1
//========================================
#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40 // LCD RAM address for the 2nd line
int8 const LCD_INIT_STRING[4] =
{
0x20 | (lcd_type << 2), // Func set: 4-bit, 2 lines, 5x8 dots
0xc, // Display on
1, // Clear display
6 // Increment cursor
};
//-------------------------------------
void lcd_send_nibble(int8 nibble){
// Note: !! converts an integer expression
// to a boolean (1 or 0).
output_high(EN_AB);
delay_us(10);
output_bit(LCD_DB4, !!(nibble & 1));
output_bit(LCD_DB5, !!(nibble & 2));
output_bit(LCD_DB6, !!(nibble & 4));
output_bit(LCD_DB7, !!(nibble &
);
output_low(EN_AB);
delay_us(10);
delay_cycles(1);
output_high(LCD_E);
delay_us(2);
output_low(LCD_E);
}
//-----------------------------------
// This sub-routine is only called by lcd_read_byte().
// It's not a stand-alone routine. For example, the
// R/W signal is set high by lcd_read_byte() before
// this routine is called.
#ifdef USE_LCD_RW
int8 lcd_read_nibble(void){
int8 retval;
// Create bit variables so that we can easily set
// individual bits in the retval variable.
#bit retval_0 = retval.0
#bit retval_1 = retval.1
#bit retval_2 = retval.2
#bit retval_3 = retval.3
retval = 0;
output_low(EN_AB);
delay_us(10);
output_high(LCD_E);
delay_cycles(1);
output_high(EN_AB);
delay_us(10);
retval_0 = input(LCD_DB4);
retval_1 = input(LCD_DB5);
retval_2 = input(LCD_DB6);
retval_3 = input(LCD_DB7);
output_low(EN_AB);
delay_us(10);
output_low(LCD_E);
return(retval);
}
#endif
//---------------------------------------
// Read a byte from the LCD and return it.
#ifdef USE_LCD_RW
int8 lcd_read_byte(void){
int8 low;
int8 high;
output_low(EN_AB);
delay_us(10);
output_high(LCD_RW);
delay_cycles(1);
high = lcd_read_nibble();
low = lcd_read_nibble();
return( (high<<4) | low);
}
#endif
//----------------------------------------
// Send a byte to the LCD.
void lcd_send_byte(int8 address, int8 n){
output_low(EN_AB);
delay_us(10);
output_low(LCD_RS);
#ifdef USE_LCD_RW
while(bit_test(lcd_read_byte(),7)) ;
#else
delay_us(60);
#endif
if(address)
{
output_low(EN_AB);
delay_us(10);
output_high(LCD_RS);
}
else
{
output_low(EN_AB);
delay_us(10);
output_low(LCD_RS);
}
delay_cycles(1);
#ifdef USE_LCD_RW
output_low(EN_AB);
delay_us(10);
output_low(LCD_RW);
delay_cycles(1);
#endif
output_low(EN_AB);
delay_us(10);
output_low(LCD_E);
lcd_send_nibble(n >> 4);
lcd_send_nibble(n & 0xf);
}
//----------------------------
void lcd_init(void){
int8 i;
output_low(EN_AB);
delay_us(10);
output_low(LCD_RS);
#ifdef USE_LCD_RW
output_low(LCD_RW);
#endif
output_low(LCD_E);
delay_ms(15);
for(i=0 ;i < 3; i++)
{
lcd_send_nibble(0x03);
delay_ms(5);
}
lcd_send_nibble(0x02);
for(i=0; i < sizeof(LCD_INIT_STRING); i++)
{
lcd_send_byte(0, LCD_INIT_STRING
);
// If the R/W signal is not used, then
// the busy bit can't be polled. One of
// the init commands takes longer than
// the hard-coded delay of 60 us, so in
// that case, lets just do a 5 ms delay
// after all four of them.
#ifndef USE_LCD_RW
delay_ms(5);
#endif
}
delay_ms(15);
}
//----------------------------
// Posiciones válidas:
// de x=1 a x=16 y
// de y=1 a y=2
void lcd_gotoxy(int8 x, int8 y){
int8 address;
if(x > 0 && y > 0){
if(y > 1)
address = lcd_line_two;
else
address=0;
address += x-1;
lcd_send_byte(0, 0x80 | address); // Manda cursor a la posición
}
}
//-----------------------------
void lcd_putc(char c)
{
/*' LCD
' Command Operation
' *********** *****************************************
' $FE, 1 Clear display
' $FE, 2 Return home
' $FE, $0C Cursor off
' $FE, $0E Underline cursor on
' $FE, $0F Blinking cursor on
' $FE, $10 Move cursor left one position
' $FE, $14 Move cursor right one position
' $FE, $80 Move cursor to beginning of first line
' $FE, $C0 Move cursor to beginning of second line
' *********** ***************************************** */
if(c>'\0'){
switch(c){
case '\f':
lcd_send_byte(0,1);
lcd_send_byte(0,2);
delay_ms(2);
break;
case '\n':
lcd_gotoxy(1,2);
delay_ms(2);
break;
case '\b':
lcd_send_byte(0,0x10);
delay_ms(2);
break;
case '\t':
lcd_send_byte(0,0x14);
delay_ms(2);
break;
default:
lcd_send_byte(1,c);
delay_ms(2);
break;
}
}
}
//------------------------------
void lcd_put_string(char *string){
//put string, starting from the curren cursor position
//assume that string not excides from lcd displayed RAM
char index=0;
while(string[index]!=0){
lcd_putc(string[index++]);
}
}
//------------------------------
void lcd_put_string_xy(char *string, char x, char y){
//assume that string not excides from lcd displayed RAM
lcd_gotoxy(x,y);
lcd_put_string(string);
}
//------------------------------
#ifdef USE_LCD_RW
char lcd_getc(int8 x, int8 y)
{
char value;
lcd_gotoxy(x,y);
// Wait until busy flag is low.
while(bit_test(lcd_read_byte(),7));
output_low(EN_AB);
delay_us(10);
output_high(LCD_RS);
value = lcd_read_byte();
output_low(EN_AB);
delay_us(10);
output_low(LCD_RS);
return(value);
}
#endif
//------------------------------
void lcd_setcursor(short visible, short blink) {
lcd_send_byte(0, 0xC|(visible<<1)|blink);
}
No encuentro el fallo.
Como sólo voy a escribir en la LCD, mantengo el puerto D entero como salidas.
Espero que me puedan ayudar.
Muchas gracias de antemano.
Un saludo.
