จำหน่ายอุปกรณ์ อิเล็กทรอนิกส์ บอร์ด Microcontroller MCS-51 AVR ARM7 PIC dsPIC PIC32

/*

* PORTB bits 0-3 are connected to the LCD data bits 4-7 (high nibble)
* PORTA bit 2 is connected to the LCD RS input (register select)
* PORTA bit 3 is connected to the LCD EN bit (enable)
*
* To use these routines, set up the port I/O (TRISA, TRISB) then
* call lcd_init(), then other routines as required.
*
*/

//Define compiler error message.
#ifndef __CPU_16F877__
#error "This program is tailored for PIC16F648A controller"
#endif

//Include required header files here.
#include "io16f877.h" //the hardware register definition file.
//-----------------------------------------------------------------delay---------------------------------------------------
//---------------------------------------------------------------------------------------------------------------------------
void DelayUs(int count)
{
int i;

int j;
for(i=0;i<count;i++)
{
for(j=0;j<5;j++);
//This for loop has 5 NOPs & wastes 1 uS for our PIC clock frequency of 20MHz.
}
}

void DelayMs(int count)
{
int i;
for(i=0;i<count;i++)
{DelayUs(4000);}
}
//---------------------------------------------------------------------------------------------------------------------------
//-----------------------------------------------------------------------------------------------------------------------------

#define LCD_RS RA2 // Register select
#define LCD_EN RA3 // Enable

#define LCD_STROBE ((LCD_EN = 1),(LCD_EN=0))


/* write a byte to the LCD in 4 bit mode */

void
lcd_write(unsigned char c)
{
PORTB = (PORTB & 0xF0) | (c >> 4);
LCD_STROBE;
PORTB = (PORTB & 0xF0) | (c & 0x0F);
LCD_STROBE;
DelayUs(40);
}

/*
* Clear and home the LCD
*/

void
lcd_clear(void)
{
LCD_RS = 0;
lcd_write(0x1);
DelayMs(2);
}

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

void
lcd_puts(const char * s)
{
LCD_RS = 1; // write characters
while(*s)
lcd_write(*s++);
}

/* write one character to the LCD */

void
lcd_putch(char c)
{
LCD_RS = 1; // write characters
PORTB = (PORTB & 0xF0) | (c >> 4);
LCD_STROBE;
PORTB = (PORTB & 0xF0) | (c & 0x0F);
LCD_STROBE;
DelayUs(40);
}


/*
* Go to the specified position
*/

void
lcd_goto(unsigned char pos)
{
LCD_RS = 0;
lcd_write(0x80+pos);
}

/* initialise the LCD - put into 4 bit mode */

void
lcd_init(void)
{
LCD_RS = 0; // write control bytes
DelayMs(15); // power on delay
PORTB = 0x2; // attention! or 0x2
LCD_STROBE; // Step 1
DelayMs(5);
LCD_STROBE; // Step 2
DelayUs(100);
LCD_STROBE; // Step 3
DelayMs(5);
PORTB = 0x2; // set 4 bit mode
LCD_STROBE; // Step 4
DelayUs(40);
lcd_write(0x28 ); // 4 bit mode, 1/16 duty, 5x8 font
lcd_write(0x08 ); // display off
lcd_write(0x0F); // display on, blink curson on
lcd_write(0x06); // entry mode
}
void IniPort()
{
ADCON1=0x06;
TRISA=0x00;
TRISB=0x00;
PORTA=0x00;
PORTB=0x00;


}

char text[]="len di\n";
int count=0;
void main(void)
{
IniPort();
lcd_init();
while (text[count]!='\n')
{
lcd_putch(text[count]);
count++;
}
DelayUs(100);
while(1){}
}