lcd1604.c

PIC18F6720写DAC7612U,TA1604_LCD显示,I2C读写PCF8563,PIC单片机之间模拟I2C通讯,该软件已调试通过,已经在产品上使用,有中文说明.

struct lcd_pin_map {                 
           BOOLEAN enable;    // enable为1位,对应RD0
           BOOLEAN rs;        // rs为1位,对应RD1
           BOOLEAN rw;        // rw为1位,对应RD2
           BOOLEAN BL_pwr;    // BL_pwr为1位,对应RD3 BL_pwr为1位,对应RD3,开关LCD背光灯
           int     data : 4;  // 声明data为4位,对应RD4,RD5,RD6,RD7
        } lcd;

#if defined(__PCH__)
#if defined use_portb_lcd
   #byte lcd = 0xF81         //使用端口PORT_b作为LCD接口(at address 0xF81)
#else
   #byte lcd = 0xF83         //使用端口PORT_D作为LCD接口(at address 0xF83)
#endif
#endif

#if defined use_portb_lcd
   #define set_tris_lcd(x) set_tris_b(x)
#else
   #define set_tris_lcd(x) set_tris_d(x)
#endif

#define lcd_type 2           // LCD为两行
#define lcd_line_two 0x40    // 第二行LCD_RAM首地址为0x40

BYTE const LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
                             // These bytes need to be sent to the LCD
                             // to start it up.


                             // The following are used for setting
                             // the I/O port direction register.

struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; //对于写方式,所有脚设置为输出
struct lcd_pin_map const LCD_READ = {0,0,0,0,15}; //对于读方式,低位4为输出,高4位data pins为输入,15为F;

BYTE lcd_read_byte() {
      BYTE low,high;         //声明暂态变量low,high,high用来存字节的高4位,low用来存字节的低4位;
      set_tris_lcd(LCD_READ);//设置端口B的低4位为输出口,端口B的高4位为输入口;
      lcd.rw = 1;            //发送LCD读命令;
      delay_cycles(1);       //相当于1个NOP指令;
      lcd.enable = 1;        //LCD使能;
      delay_cycles(1);
      high = lcd.data;       //读LCD端口的数据高4位;
      lcd.enable = 0;        //LCD不使能;
      delay_cycles(1);
      lcd.enable = 1;        //LCD使能;
      delay_us(1);           //延时1us;
      low = lcd.data;        //读LCD端口的数据低4位;
      lcd.enable = 0;        //LCD不使能;
      set_tris_lcd(LCD_WRITE);  //设置控制LCD端口B为输出口
      return( (high<<4) | low); //合并字节的高4位和字节的低4位,组成1个字节,返回
}

void lcd_send_nibble( BYTE n ) {
      lcd.data = n;
      delay_cycles(1);  //相当于1个NOP指令;
      lcd.enable = 1;   //LCD使能;
      delay_us(2);      //延时1us;
      lcd.enable = 0;   //LCD不使能;
}


/* address=0选择命令寄存器,则n为命令字;若address=1选择数据寄存器,则n为显示数据 */
void lcd_send_byte( BYTE address, BYTE n ) {

      lcd.rs = 0;                              //选择LCD的地址寄存器;
      while ( bit_test(lcd_read_byte(),7) ) ;  //bit_test(X,b)位测试涵数,测试LCD是否忙;
      lcd.rs = address;                        //选择LCD的地址寄存器
      delay_cycles(1);                         //相当于1个NOP指令;
      lcd.rw = 0;                              //向LCD发送写命令;
      delay_cycles(1);                         //相当于1个NOP指令;
      lcd.enable = 0;                          //LCD不使能;
      lcd_send_nibble(n >> 4);                 //向LCD写数据n的高4位;
      lcd_send_nibble(n & 0xf);                //向LCD写数据n的低4位;
}


/* 通过x和y的坐标取得真正的LCD_RAM地址,并发送写地址命令  */
void lcd_gotoxy( BYTE x, BYTE y) {
   BYTE address;           //声明暂态变量address;

   if(y!=1)
     address=lcd_line_two; //将LCD_RAM的第2行首地址0x40送给address;
   else
     address=0;            //将LCD_RAM的第1行首地址0x00送给address;
   address+=x-1;           //通过x和y的坐标取得真正的LCD_RAM地址;
   lcd_send_byte(0,0x80|address);  //向LCD发送写地址命令
}

/* 向LCD写数据 */
void lcd_putc( char c) {
   switch (c) {
     case '\f'   : lcd_send_byte(0,1);            //若c是走纸换页符('\f'),则执行该行;
                   delay_ms(2);
                                           break; 
     case '\n'   : lcd_gotoxy(1,2);        break; //若c是换行符('\n'),则执行该行;
     case '\b'   : lcd_send_byte(0,0x10);  break; //若c是退格符('\b'),则执行该行;
     default     : lcd_send_byte(1,c);     break;
   }
}


/* 根据x和y的坐标读取LCD的数据  */
char lcd_getc( BYTE x, BYTE y) {
   char value;

    lcd_gotoxy(x,y);  //向LCD写写地址
    while ( bit_test(lcd_read_byte(),7) ); //若LCD忙,则等待
    lcd.rs=1;
    value = lcd_read_byte();  //读指定坐标位置的数据
    lcd.rs=0;
    return(value);
}


/* LCD初始化函数  */
void lcd_init() {
    BYTE i;                   //声明暂态变量i;
    output_high(PIN_E7);      //开LCD电源
    set_tris_lcd(LCD_WRITE);  //设置控制LCD端口B为输出口;
    lcd.rs = 0;               //选择LCD的地址寄存器;
    lcd.rw = 0;               //向LCD发送写命令;
    lcd.enable = 0;           //LCD不使能;
    delay_ms(15);             //延时15ms;
    for(i=1;i<=3;++i) {
       lcd_send_nibble(3);    //将0x333送给LCD;
       delay_ms(5);           //延时5ms
    }
    lcd_send_nibble(2);       //将0x2333送给LCD;
    for(i=0;i<=3;++i)
       lcd_send_byte(0,LCD_INIT_STRING[i]);
       lcd.BL_pwr=1;          //开LCD背光灯
   lcd_putc("\fReady...\n");
   delay_ms(1000);
   lcd_putc("\fOutput: 0.00mA\n");  //显示Output:  0.00mA
}





void lcd1604_display(*display_pointer){
   int lcd_counter=0;
   int lcd_temp;
   lcd_gotoxy(8,1);  //计算坐标(8,1)处的LCD_RAM地址
   if( *(display_pointer)=='0' )
     { lcd_putc(" ");
       lcd_counter++;
     }
   for(; lcd_counter<5;lcd_counter++)
     {
      lcd_temp=*(display_pointer+lcd_counter);
      lcd_putc(lcd_temp);
     }
}