lcd.lst

利用热释红外传感器、12C887和PIC单片机制作的智能电子时钟

     1: /*
     2:  *  LCD interface example
     3:  *  Uses routines from delay.c
     4:  *  This code will interface to a standard LCD controller
     5:  *  like the samsung KS0066. It uses it in 4 bit mode, with
     6:  *  the hardware connected as follows (the standard 16 pin
     7:  *  LCD connector is used):
     8:  *
     9:  *  PORTC bits 4-7 are connected to the LCD data bits 4-7 (high nibble)
    10:  *  PORTA bit 1 is connected to the LCD RS input (register select)
    11:  *  PORTA bit 2 is connected to the LCD EN bit (enable)
    12:  *
    13:  *  To use these routines, set up the port I/O (TRISC, TRISB) then
    14:  *  call lcd_init(), then other routines as required.
    15:  *
    16:  */
    17: 
    18: #include <pic.h>
    19: #include "lcd.h"
    20: #include "delay.h"
    21: 
    22: #define TLCD_RS  TRISA1
    23: #define TLCD_EN  TRISA2
    24: #define TLCD_A   TRISA3
    25: #define LCD_RS   RA1   // 寄存器选择
    26: #define LCD_EN   RA2   // 使能
    27: #define LCD_A    RA3   // 背光,RA4开漏输出,欲输出1,需要外接上拉电阻
    28: 
    29: #define LCD_STROBE  ((LCD_EN = 1),(LCD_EN=0))
    30: #define LCD_CURSOR(x)   lcd_write(((x)&0x7F)|0x80)
    31: 
    32: /* light lcd & dark*/
    33: 
    34: void lcd_light(void)
    35: {
    36:     LCD_A = 0;
    37: }
    38: 
    39: void lcd_dark(void)
    40: {
    41:     LCD_A = 1;
    42: }
    43: 
    44: 
    45: /* write a byte to the LCD in 4 bit mode */
    46: 
    47: void lcd_write(unsigned char c)
    48: {
    49:     PORTC = (PORTC & 0x0F) |  (c &0xF0);
    50:     LCD_STROBE;
    51:     PORTC = (PORTC & 0x0F) |  (c<<4);
    52:     LCD_STROBE;
    53:     DelayUs(40);
    54: }
    55: 
    56: /* Clear and home the LCD */
    57: 
    58: void lcd_clear(void)
    59: {
    60:     LCD_RS = 0;
    61:     lcd_write(0x1);
    62:     DelayMs(2);
    63: }
    64: 
    65: /* write a string of chars to the LCD */
    66: 
    67: void lcd_puts(const char * s)
    68: {
    69:     LCD_RS = 1; // write characters
    70:     while(*s)//当S的值不为0时,执行,故,需要花一个RAM,将其清0作为整个字符数组的结束标记
    71:     {
    72:         lcd_write(*s++);
    73:     }
    74: }
    75: 
    76: 
    77: /* write one character to the LCD */
    78: 
    79: void lcd_putch(char c)
    80: {
    81:     LCD_RS = 1; // write characters
    82:     PORTC = (PORTC & 0x0F) |  (c &0xF0);
    83:     LCD_STROBE;
    84:     PORTC = (PORTC & 0x0F) |  (c<<4);
    85:     LCD_STROBE;
    86:     DelayUs(40);
    87: }
    88: 
    89: /* Go to the specified position */
    90: 
    91: void lcd_goto(unsigned char pos)
    92: {
    93:     LCD_RS = 0;
    94:     LCD_CURSOR(pos);
    95: }
    96: 
    97: /* initialise the LCD - put into 4 bit mode */
    98: #ifndef SPLC780D
    99: void lcd_init(void)
   100: {
   101: 
   102:     TLCD_RS = 0;
   103:     TLCD_EN = 0;
   104:     TLCD_A  = 0;
   105:     LCD_RS = 0;
   106:     LCD_EN = 0;
   107:     LCD_A  = 0;
   108:     LCD_RS = 0;         // write control bytes
   109:     lcd_write(0x2);     // return home
   110:     DelayMs(2);
   111:     lcd_write(0x28);    // 4 bit mode, 2 lines, 5x7 font
   112:     lcd_write(0x0C);    // display on, curson off, blink off
   113:     lcd_clear();        // clear display
   114:     lcd_write(0x06);    // right, increment address
   115: }
   116: #else
   117: void lcd_init(void)
   118: {
   119: 
   120:     TLCD_RS = 0;
   121:     TLCD_EN = 0;
   122:     TLCD_A  = 0;
   123:     LCD_RS = 0;
   124:     LCD_EN = 0;
   125:     LCD_A  = 0;
   126:     LCD_RS = 0;         // write control bytes
   127:     lcd_write(0b00000010);  // return home
   128:     DelayMs(10);
   129:     lcd_write(0b00111111);  // 8 bit interface
   130:     DelayMs(10);
   131:     lcd_write(0b00111111);  // 8 bit interface
   132:     DelayMs(10);
   133:     lcd_write(0b00101000);  // 4 bit interface,2 lines,5*8
   134:     DelayMs(10);
   135:     lcd_write(0b00001100);  // dispaly on
   136:     DelayMs(10);
   137:     lcd_write(0b00000001);  // clear LCD
   138:     DelayMs(10);
   139:     lcd_write(0b00000110);  // entry mode set
   140:     DelayMs(10);
   141: }
   142: #endif