LCD mit PIC16 ansteuern

/* This is a simple demo project written for use with

 * the HI-TECH Software PICC compiler. It may be compiled

 * and run on the Microchip PICDEM 2 PLUS DEMO BOARD.

 * Features demonstrated include driving the LCD display and

 * the A2D converter. 

 Additional files required for this demo are included in the

 PIC\SAMPLES directories:

 DELAY\delay.c

 DELAY\delay.h

 lcd.c

 lcd.h

 */

#include <htc.h>

#include <stdio.h>

//#include <pic16f887.h>

#include "lcd.h"

#include "delay.h"

//#include "picdem2_lcd_htc.h"

/* this is the maximum value of an A2D conversion. */

#define MAXVOLTAGE 5

void init(void){

  lcd_init(FOURBIT_MODE);

  ADON=1;  /* enable A2D converter */

  ADIE=0;  /* not interrupt driven */

  ADCON1=0x0E;

  ADCON0=1;

  TRISB=0x00;  // Set PORTB in output mode

  T1CON=0x31;  // turn on timer 1

  TMR1IE=1;  // timer 1 is interrupt enabled

  PEIE=1;    // enable peripheral interrupts

  GIE=1;    // turn on interrupts

}

void interrupt isr(void){

  if(TMR1IE && TMR1IF){

    PORTB++;

    TMR1IF=0;

  }

}

void main(void){

  unsigned char last_value;

  unsigned char volts;

  unsigned char decivolts;

  unsigned char outString[20];

  init();

  lcd_clear();

  DelayMs(500);

  DelayMs(500);

  DelayMs(500);

  lcd_puts("test");  

  while(1)

  {

  }

}

/*

 *  LCD interface example

 *  Uses routines from delay.c

 *  This code will interface to a standard LCD controller

 *  like the Hitachi HD44780. It uses it in 4 or 8 bit mode

 *  

 */

#include  <htc.h>

//#include <pic16f887.h>

#include  "lcd.h"

static bit fourbit;    // four or eight bit mode?

#ifdef CHECKBUSY

unsigned char 

lcd_read_cmd_nowait(void)

{

  unsigned char c, readc;

  LCD_DATA_TRIS   |=  ~OUTPUT_DATA;  // Set data lines to input

  LCD_RW = 1; // Read LCD

  _delay(2); // short propagation delay

  if (fourbit) {

    LCD_STROBE_READ(readc); // Read high nibble

    // Move 4 bits to high nibble while zeroing low nibble

    c = ( ( readc << 4 ) & 0xF0 ); 

    LCD_STROBE_READ(readc); // Read low nibble

        c |= ( readc & 0x0F ); // Or in 4 more bits to low nibble

  } else {

    LCD_STROBE_READ(readc); 

    c = readc;

  }

  LCD_RW = 0; // Return to default mode of writing LCD

  LCD_DATA_TRIS &= OUTPUT_DATA; // Return to default mode of writing LCD

  return(c);

}

void

lcd_check_busy(void) // Return when the LCD is no longer busy, or we've waiting long enough!

{

  // To avoid hanging forever in event there's a bad or 

  // missing LCD on hardware.  Will just run SLOW, but still run.

  unsigned int retry; 

  unsigned char c;

  for (retry=1000; retry-- > 0; ) {

    c = lcd_read_cmd_nowait();

    if (0==(c&0x80)) break; // Check busy bit.  If zero, no longer busy

  }

}

#endif

void

lcd_send(unsigned char c)

{  

  LCD_EN = 1;

  if (fourbit) {

    LCD_TX(c>>4);  // load upper nibble

    LCD_EN = 0;

    NOP();

    NOP();

    LCD_EN = 1;

    LCD_TX(c);  // load lower nibble

  } else {

    LCD_DATA = c;  // load both nibbles

  }

  LCD_EN = 0;

}

/* send a command to the LCD */

void

lcd_cmd(unsigned char c)

{

  LCD_WAIT; // may check LCD busy flag, or just delay a little, depending on lcd.h

  LCD_RS = 0;

  lcd_send(c);

}

/* send data to the LCD */

void

lcd_data(unsigned char c)

{

  LCD_WAIT; // may check LCD busy flag, or just delay a little, depending on lcd.h

  LCD_RS = 1;

  lcd_send(c);

  LCD_RS = 0;

}

/* write a string of chars to the LCD */

void

lcd_puts(const char * s)

{

  while(*s)

    lcd_data(*s++);

}

/* initialize the LCD */

void

lcd_init(unsigned char mode)

{

  char init_value;

  fourbit    = 0;

  if (mode == FOURBIT_MODE){

    fourbit = 1;

    init_value = 0x3;

  }else{

    init_value = 0x3F;

  }

#if (_PICDEM2_REVISION_ == 6)

  LCD_CTRL &= 0x0F;

  // All data and control lines on same TRIS register

  LCD_DATA_TRIS   &= (OUTPUT_DATA & OUTPUT_CTRL);

  LCD_VCC = 1;  // turn on the power to the LCD

#else

  LCD_RS = 0;

  LCD_EN = 0;

  LCD_RW = 0;

  // Set control lines digital

  ADCON1 = 7;

  // Set control lines to output

  LCD_RS_TRIS   = OUTPUT_PIN;

  LCD_EN_TRIS   = OUTPUT_PIN;

  LCD_RW_TRIS   = OUTPUT_PIN;

  // Set data lines to output

  LCD_DATA_TRIS   &= OUTPUT_DATA;

#endif

  __delay_ms(15);

  LCD_EN = 1;

  LCD_TX(init_value);

  LCD_EN = 0;

  __delay_ms(5);

  LCD_EN = 1;

  LCD_DATA |= init_value;

  LCD_EN = 0;

  __delay_us(200);

  LCD_EN = 1;

  LCD_DATA |= init_value;

  LCD_EN = 0;

  __delay_us(200);

  if (fourbit){

    LCD_WAIT;  //may check LCD busy flag, or just delay a little, depending on lcd.h

    LCD_EN = 1;

    LCD_TX(0x2);  // Set 4-bit mode

    LCD_EN = 0;

    lcd_cmd(0x28);  // Function Set

  }else{

    lcd_cmd(0x38);

  }

  lcd_cmd(0xF); //Display On, Cursor On, Cursor Blink

  lcd_clear(); //Display Clear

  lcd_cmd(0x6); //Entry Mode

  lcd_goto(0); //Initialize DDRAM address to zero

}