lcd_2.c

一个c51的时钟事例程序

//File: C:\comms\eaglhome\codefrag\lcd44780.c 28/01/99, 11:52:05
/*********************************************************************************************/
/* Program : LCD44780.C */
/* Function : LCD Control Procedures for HD44780 Controller */
/* Author : John F. Fitter B.E. */
/* */
/* Description : Procedures to drive the Hitachi LCD module - 1 to 4 line x nn char */
/* - in 4 bit mode */
/* */
/* Useage : lcd_init() Must be called before any other function */
/* putch(chr) Display chr at the current cursor position */
/* This is stdout for the Hitech compiler */
/* The following have special meaning; */
/* \f Clear display */
/* \n Goto start of next line */
/* \r Goto start of current line */
/* \b Backspace one position */
/* lcd_gotoxy(c) Set cursor position on LCD, Upper left is (0,0) */
/* c : bits 0..4 = character position in line */
/* c : bits 5..6 = line number */
/* c : bit 7 = cursor on status */
/* In the case of single line displays the lower 6 bits*/
/* are the character position. */
/* lcd_shift(n) Shifts display n chars, +ve for right, -ve for left */
/* lcd_write_cgram(c,p) Writes a cgram character line pattern to the cgram. */
/* c = character position to write */
/* p = character pattern to write */
/* lcd_blank_display(b) Blank or restore the display restoring the cursor */
/* status also. b is true to blank the display. */
/* */
/* Rev No. Rev date Test date Test platform Description */
/* ------- -------- --------- --------------- ----------------------------------- */
/* 00 6jun98 Original in HiTech C */
/* 01 25jun98 Total rewrite of lcd_gotoxy */
/* Improved lcd_shift */
/* */
/* Copyright . 1998 Eagle Air Australia Pty. Ltd. All rights reserved */
/*********************************************************************************************/
#define _LCD44780_C
#include <commdefs.h>
#include "main.h"
#include "lcd44780.h"
#include "1306spi.h"
#include "delays.h"
#include "serial.h"
#include "25cxxspi.h"
#include "e2data.h"
void lcd_send_byte(unsigned char address, unsigned char chr) {
unsigned char rVal;
LCDPORTDIR = LCD_READ; // set data/con port directions
lcd_select_reg(CMD_REG);  // select command register
lcd_select_dir(READ_DIR);  // set lcd to read
do { // wait until lcd is ready
lcd_set_clk_hi();// toggle data clock
rVal = lcd_get_data(); // read high nibble from data bus
lcd_set_clk_lo();
delay_500ns();
lcd_toggle_clk(); // toggle data clock
} while(!!(rVal & (HINIBBLE(LCD_BUSY))));
LCDPORTDIR = LCD_WRITE; // set data/con port directions
lcd_select_reg(address);  // select desired register
lcd_select_dir(WRITE_DIR);  // set to write
lcd_set_data(HINIBBLE(chr)); // send the high nibble
lcd_toggle_clk(); // toggle data clock
lcd_set_data(chr);  // send the low nibble
lcd_toggle_clk();  // toggle data clock
}
// Procedure to initialise the lcd for 4 bit operation.
// This procedure implements the "Initialisation by instruction" as described for
// Philips PCF2116X
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File: C:\comms\eaglhome\codefrag\lcd44780.c 28/01/99, 11:52:05
void init_lcd() {
unsigned char n;
LCDPORTDIR = LCD_WRITE; // set data/con & enable port dir’ns
lcd_set_clk_lo();  // set data clock low (enable pin)
lcd_select_reg(CMD_REG); // select command register
lcd_select_dir(WRITE_DIR);// set to write
delay_ms(15);// wait > 15ms Vdd rises above Vpor
lcd_set_data(HINIBBLE(LCD_FNSET | LCD_8BIT));  // put nibble on data bus
for (n = 0; n < 3; ++n) {  // set mode to 8 bit data 3 times
lcd_toggle_clk();  // toggle data clock
delay_ms(5);  // 5ms delay
}
#ifdef LCD1LINES && (LCDNCHARS > 16)
lcd_set_data(HINIBBLE(LCD_FNSET));  // set mode to 4 bit data and 1 line
lcd_toggle_clk(); // toggle data clock
lcd_send_byte(LCD_COMMAND, LCD_FNSET);
#else
#ifdef LCD4LINES
lcd_set_data(HINIBBLE(LCD_FNSET | LCD_4LINE));  // set mode to 4 bit data and 4 lines
lcd_toggle_clk(); // toggle data clock
lcd_send_byte(LCD_COMMAND, LCD_FNSET | LCD_4LINE);
#else
lcd_set_data(HINIBBLE(LCD_FNSET | LCD_2LINE));// set mode to 4 bit data and 2 lines
lcd_toggle_clk();  // toggle data clock
lcd_send_byte(LCD_COMMAND, LCD_FNSET | LCD_2LINE); // (applies to 16x1 also - odd one!!)
#endif
#endif
lcd_send_byte(LCD_COMMAND, LCD_DISPON | LCD_DISP_ALL); // display on
lcd_send_byte(LCD_COMMAND, LCD_CLR); // clear the display
lcd_send_byte(LCD_COMMAND, LCD_EMSET | LCD_EM_INC); // entry mode to increment
LCDPORTDIR = LCD_READ; // set data/con port dir’ns
linenum = 0; // set line number to first line
disp_blank = false; // flag display as visible
cursor_on = false; // flag the cursor as off
}
// Moves the cursor to posline. The first character position is 0 and the first line is 0
// If the cursor bit is set then a blinking cursor location is shown else the blinking
// is removed. The procedure returns the old cursor status.
// Definition of posline : bits 0..4 = character position in line (left = 0)
// bits 5..6 = line number (top = 0)
// bit 7 = cursor status (on = 1)
// In the case of single line displays the lower 6 bits are the character position.
unsigned char lcd_gotoxy(unsigned char posline) {
unsigned char address, cstat;
cstat = cursor_on;
if(c_status.prt_to_lcd) {
#ifdef LCD1LINES // this method is faster than using the
linenum = 0; // modulus operator but more verbose
address = posline & 0x3f;
#else
linepos = posline & 0x1f; // save the line char position
linenum = (posline >> 5) & 3; // save the line number
#ifdef LCD2LINES
if(linenum > 1) linenum = 0; // 2 line display ?
#else
if(linenum > 3) linenum = 0; // 4 line display ?
#endif // LCD2LINES
address = linepos;
if(linenum == 1) address += STRT_LINE2; // set ram address to (pos,line)
else if(linenum == 2) address += STRT_LINE3;
else if(linenum == 3) address += STRT_LINE4;
#endif // LCD1LINES
lcd_send_byte(LCD_COMMAND, LCD_DD_SET | address);
if(!!(posline & 0x80) != cursor_on) {  // has the cursor status changed ?
cursor_on = !!(posline & 0x80);
if(disp_blank) lcd_send_byte(LCD_COMMAND, LCD_DISPON);
else if(cursor_on) lcd_send_byte(LCD_COMMAND, LCD_DISPON |
LCD_DISP_ALL | LCD_DISP_BLNK);
else lcd_send_byte(LCD_COMMAND, LCD_DISPON|LCD_DISP_ALL);
}
}
return cstat;
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}
// Blank or restore the display restoring the cursor status also.
void lcd_blank_display(unsigned char blank) {
disp_blank = blank;
if(disp_blank) lcd_send_byte(LCD_COMMAND, LCD_DISPON);
else if(cursor_on) lcd_send_byte(LCD_COMMAND, LCD_DISPON | LCD_DISP_ALL | LCD_DISP_BLNK);
else lcd_send_byte(LCD_COMMAND, LCD_DISPON|LCD_DISP_ALL);
}
// If the print flag is set to lcd then writes a character to the display at cursor. Backspace,
// newline and formfeed are recognised. Formfeed clears the display, newline moves the cursor
// to the start of the second line. Programmable characters have codes between 0x0f and 0x1f.
// They are mapped to cgram, 0x0 to 0xf. This makes all of the cgram available to programmable
// characters and also allows string printing without premature termination on 0.
// If the print flag is set to serial then the character is sent directly to the serial port.
void putch(char chr) {
if(c_status.prt_to_lcd) {  // printing to lcd
if(chr == ’\f’) {
lcd_send_byte(LCD_COMMAND, LCD_CLR);  // formfeed clears the display
linenum = 0; // set line number to first line
}
// Newline to start of next line.
else if(chr == ’\n’) lcd_gotoxy((cursor_on ? 0x80 : 0) | ((linenum + 1) << 5));
// Return to start of current line.
else if(chr == ’\r’) lcd_gotoxy((cursor_on ? 0x80 : 0) | (linenum << 5));
// Backspace.
else if(chr == ’\b’) lcd_send_byte(LCD_COMMAND, LCD_SHIFT);
// Other characters.
else {
if((chr < 0x20)&&(chr > 0x0f)) chr -= 0x10; // translate special characters
lcd_send_byte(LCD_DATA, chr);  // write at current cursor position
}
}else { // printing to usart
if(chr == 0x11) chr = xl_super2; // translate superscript 2
putch_ser(chr); // send char to serial port
if(chr == ’\n’) putch_ser(’\r’); ); // ma cr/lf pair if required
}
}
// Clear m characters on the lcd by writing m spaces then m backspaces.
void clear_line(unsigned char m) {
unsigned char n = m;
if(c_status.prt_to_lcd) {
while(n--) lcd_send_byte(LCD_DATA, ’ ’);
while(m--) lcd_send_byte(LCD_COMMAND, LCD_SHIFT);
}
}
// Shift the screen left or right. npos is the number of character positions to shift,
// +ve for right and -ve for left.
/*
void lcd_shift(signed char npos) {
unsigned char command command;
command = LCD_SHIFT | LCD_DISP_SHFT SHFT;
if(npos > 0) command |= LCD_SHFT_RT RT;
else npos = -npos npos;
while(npos--) lcd_send_byte(LCD_COMMAND, command) command);
}
*/
// Writes a cgram character line pattern to the cgram.
void lcd_write_cgram(unsigned char address, unsigned char pattern) {
lcd_send_byte(LCD_COMMAND, (address & 0x3f) | LCD_CG_SET); // set cgram addr.
lcd_send_byte(LCD_DATA, pattern);
}
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File: C:\comms\eaglhome\codefrag\lcd44780.c 28/01/99, 11:52:05
// ***** EOF LCD44780.C *****
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