maruco
17-09-2010, 11:04 PM
Em thấy trên diễn đàn cũng có bài về menu lcd nhưng em thấy ko có bài nào hướng dẫn cụ thể . Bác nào có chương trình mẫu cho em xin em cảm ơn !!
dinhminh09
19-09-2010, 03:57 PM
#include <16F877a.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
#include <Flex_LCD420.c>
//===================================
void main()
{
int8 i;
int8 b1, b2, b3, b4;
// The lcd_init() function should always be called once,
// near the start of your program.
lcd_init();
// Clear the LCD.
printf(lcd_putc, "\f");
delay_ms(500);
while(1)
{
// Test the clear screen and newline commands.
// Also test that we can write to all 4 lines.
printf(lcd_putc, "\fThis is the 1st line");
printf(lcd_putc, "\nNext is the 2nd line");
printf(lcd_putc, "\nThis is the 3rd line");
printf(lcd_putc, "\nFinally the 4th line");
delay_ms(3000);
// Test some additional characters.
printf(lcd_putc, "\fABCDEFGHIJKLMNOPQRST");
printf(lcd_putc, "\nabcdefghijklmnopqrst");
printf(lcd_putc, "\n12345678901234567890");
printf(lcd_putc, "\n!@#$^&*(){}[]:;<>?/=");
delay_ms(3000);
// Clear the LCD.
printf(lcd_putc, "\f");
delay_ms(500);
// Test that lcd_gotoxy() works. Go to each of
// the four corners and put a number in each one,
// in a clockwise direction, starting with the upper
// left corner.
lcd_gotoxy(4, 2);
printf(lcd_putc, "Put a number in");
lcd_gotoxy(4, 3);
printf(lcd_putc, "each corner.");
lcd_gotoxy(1, 1);
printf(lcd_putc, "1");
lcd_gotoxy(20, 1);
printf(lcd_putc, "2");
lcd_gotoxy(20, 4);
printf(lcd_putc, "3");
lcd_gotoxy(1, 4);
printf(lcd_putc, "4");
delay_ms(3000);
// Read the character that was written in each corner
// of the LCD and display it. This tests the lcd_getc()
// function.
// The following test can only be done if we can read
// from the LCD. If the RW pin is not used, then the
// LCD is in write-only mode, and we can't do this test.
// The #ifdef statement will prevent the code from
// being compiled, in that case.
#ifdef USE_RW_PIN
// Test if lcd_getc() can read
// a byte from each corner.
b1 = lcd_getc(1,1);
b2 = lcd_getc(20,1);
b3 = lcd_getc(20,4);
b4 = lcd_getc(1,4);
lcd_gotoxy(1, 1);
printf(lcd_putc, "\fRead these bytes\n");
printf(lcd_putc, "from the 4 corners:\n\n");
printf(lcd_putc, " %c %c %c %c", b1, b2, b3, b4);
delay_ms(3000);
#endif
// Type some characters and backspace over them.
printf(lcd_putc, "\fType characters and\n");
printf(lcd_putc, "backspace over them.");
delay_ms(2000);
// Go to end of 2nd line.
lcd_gotoxy(20, 2);
// Backspace over 2nd line.
for(i = 0; i < 20; i++)
{
printf(lcd_putc," \b\b");
delay_ms(150);
}
// Go to end of first line.
lcd_gotoxy(20, 1);
// Backspace over first line.
for(i = 0; i < 20; i++)
{
printf(lcd_putc," \b\b");
delay_ms(150);
}
}
}
đọc rõ file bạn sẽ vẽ được phần cưng
// Flex_LCD420.c
// These pins are for my Microchip PicDem2-Plus board,
// which I used to test this driver.
// An external 20x4 LCD is connected to these pins.
// Change these pins to match your own board's connections.
#define LCD_DB4 PIN_D4
#define LCD_DB5 PIN_D5
#define LCD_DB6 PIN_D6
#define LCD_DB7 PIN_D7
#define LCD_RS PIN_D2
#define LCD_RW PIN_D1
#define LCD_E PIN_D0
/*
// To prove that the driver can be used with random
// pins, I also tested it with these pins:
#define LCD_DB4 PIN_D4
#define LCD_DB5 PIN_B1
#define LCD_DB6 PIN_C5
#define LCD_DB7 PIN_B5
#define LCD_RS PIN_D2
#define LCD_RW PIN_D1
#define LCD_E PIN_D0
*/
// If you want only a 6-pin interface to your LCD, then
// connect the R/W pin on the LCD to ground, and comment
// out the following line. Doing so will save one PIC
// pin, but at the cost of losing the ability to read from
// the LCD. It also makes the write time a little longer
// because a static delay must be used, instead of polling
// the LCD's busy bit. Normally a 6-pin interface is only
// used if you are running out of PIC pins, and you need
// to use as few as possible for the LCD.
#define USE_RW_PIN 1
// These are the line addresses for most 4x20 LCDs.
#define LCD_LINE_1_ADDRESS 0x00
#define LCD_LINE_2_ADDRESS 0x40
#define LCD_LINE_3_ADDRESS 0x14
#define LCD_LINE_4_ADDRESS 0x54
// These are the line addresses for LCD's which use
// the Hitachi HD66712U controller chip.
/*
#define LCD_LINE_1_ADDRESS 0x00
#define LCD_LINE_2_ADDRESS 0x20
#define LCD_LINE_3_ADDRESS 0x40
#define LCD_LINE_4_ADDRESS 0x60
*/
//========================================
#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines(or more)
int8 lcd_line;
int8 const LCD_INIT_STRING[4] =
{
0x20 | (lcd_type << 2), // Set mode: 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_bit(LCD_DB4, !!(nibble & 1));
output_bit(LCD_DB5, !!(nibble & 2));
output_bit(LCD_DB6, !!(nibble & 4));
output_bit(LCD_DB7, !!(nibble & 8));
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_RW_PIN
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_high(LCD_E);
delay_us(1);
retval_0 = input(LCD_DB4);
retval_1 = input(LCD_DB5);
retval_2 = input(LCD_DB6);
retval_3 = input(LCD_DB7);
output_low(LCD_E);
delay_us(1);
return(retval);
}
#endif
//---------------------------------------
// Read a byte from the LCD and return it.
#ifdef USE_RW_PIN
int8 lcd_read_byte(void)
{
int8 low;
int8 high;
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(LCD_RS);
#ifdef USE_RW_PIN
while(bit_test(lcd_read_byte(),7)) ;
#else
delay_us(60);
#endif
if(address)
output_high(LCD_RS);
else
output_low(LCD_RS);
delay_cycles(1);
#ifdef USE_RW_PIN
output_low(LCD_RW);
delay_cycles(1);
#endif
output_low(LCD_E);
lcd_send_nibble(n >> 4);
lcd_send_nibble(n & 0xf);
}
//----------------------------
void lcd_init(void)
{
int8 i;
lcd_line = 1;
output_low(LCD_RS);
#ifdef USE_RW_PIN
output_low(LCD_RW);
#endif
output_low(LCD_E);
// Some LCDs require 15 ms minimum delay after
// power-up. Others require 30 ms. I'm going
// to set it to 35 ms, so it should work with
// all of them.
delay_ms(35);
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[i]);
// 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 50 us, so in
// that case, lets just do a 5 ms delay
// after all four of them.
#ifndef USE_RW_PIN
delay_ms(5);
#endif
}
}
//----------------------------
void lcd_gotoxy(int8 x, int8 y)
{
int8 address;
switch(y)
{
case 1:
address = LCD_LINE_1_ADDRESS;
break;
case 2:
address = LCD_LINE_2_ADDRESS;
break;
case 3:
address = LCD_LINE_3_ADDRESS;
break;
case 4:
address = LCD_LINE_4_ADDRESS;
break;
default:
address = LCD_LINE_1_ADDRESS;
break;
}
address += x-1;
lcd_send_byte(0, 0x80 | address);
}
//-----------------------------
void lcd_putc(char c)
{
switch(c)
{
case '\f':
lcd_send_byte(0,1);
lcd_line = 1;
delay_ms(2);
break;
case '\n':
lcd_gotoxy(1, ++lcd_line);
break;
case '\b':
lcd_send_byte(0,0x10);
break;
default:
lcd_send_byte(1,c);
break;
}
}
//------------------------------
#ifdef USE_RW_PIN
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_high(LCD_RS);
value = lcd_read_byte();
output_low(LCD_RS);
return(value);
}
#endif
phamchihieu
19-09-2010, 04:23 PM
cho hỏi cái đoạn code này viết cho mạch như nào. mà toàn giải thích bằng tiếng anh ko ah
không hiếu mấy .
dinhminh09
19-09-2010, 06:20 PM
cho hỏi cái đoạn code này viết cho mạch như nào. mà toàn giải thích bằng tiếng anh ko ah
không hiếu mấy .
một chương trình hiên thi lcd đơn giản
#include <16f877a.h>
#FUSES NOWDT, xt, NOPUT, NOPROTECT, NODEBUG, NOBROWNOUT, NOLVP, NOCPD, NOWRT
#use delay(clock=4000000)
#include <lcd.c> // Thu vien ham cho LCD
void main()
{
set_tris_a (0xFF);
set_tris_b (0x00);
set_tris_d (0x00);
LCD_init();
lcd_putc("hoi nhieu bi do");
lcd_putc('/n'); //xuong hang
lcd_putc("em con nho");
}
// D0 enable
// D1 rs
// D2 rw
// D4 D4
// D5 D5
// D6 D6
// D7 D7
stupid11
17-03-2011, 10:18 PM
Em thấy trên diễn đàn cũng có bài về menu lcd nhưng em thấy ko có bài nào hướng dẫn cụ thể . Bác nào có chương trình mẫu cho em xin em cảm ơn !!
bạn chỉ cần nhớ 2 chương trình con này là ok
LCD chế độ 8 BIT
porte:điều khiển
portd:ngõ ra.
//////////////////////
bit e=porte.0
bit rs=porte.1
bit rw=porte.2
/////////////////////
void lenh() //nối với thanh ghi IR điều khiển lệnh//
{
rs=0;
rw=0;
e=1;
e=0;
delay_ms(5);
}
////////////////////
void xuat() //nối với thanh ghi DR điều khiển ghi dữ liệu.
{
e=1;
rs=0;
rw=0;
e=0;
delay_ms(5);
}
//////////////////
tiếp theo bạn nên có bảng mã lệnh của LCD.
VD:
portd=0x01;
lenh(); //tức là xóa LCD
portd=0x38;
lenh(); //khởi tạo 2 dòng LCD
.....
VD:
portd="a"
xuat(); //xuất kí tự "a" ra LCD
VD:
const char mang[]="MICROCHIP"
for(i=0;i<15;i++)
{
portd=mang[i];
xuat();
delay_ms(10);
}
//xuất chữ MICROCHIP len man hình LCD//
nếu bạn mới học LCD thì không nên sử dụng các driver hỗ trợ sẵn của PIC-C.Nên sử dụng chương trỉnh này.Mình có gửi vài VD về LCD ở trên diễn đàn bạn tìm mà tham khảo.
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