8位动态LED数码管显示实验

8.1 实物图与原理图
                  本实验仪配置带8位动态扫描显示模块一个。实物图如下：
                  为减少IO的使用，我们采用串入并出芯片CD4094来扩展了IO口，即采用3个IO来实现数据的传输。
                  原理图如下：
所以，我们占用3个IO来传输数据，8个IO来进行8个LED数码管的位选。
                  在本实验仪中链接管教分布如下：
                  STK-----P2.5
                  DAT-----P2.6
                  CLK-----P2.7
                  B0、B1、B2、B3、 B4、 B5、 B6、 B7接P0口（P0.0 P0.1 P0.2 P0.3 P0.4 P0.5
                  P0.6 P0.7）
                  由于上一节已经讲述了CD4094驱动一位LED数码管的问题，这里我们讲如何来扫描8位数码管。
                  8.2 LED动态显示原理
                  根据原理图管脚连接，我们知道P0口控制了8个LED数码管的位选中，所以如果想让8个数码管都亮起来，我们可以逐位扫描8位数码管。
                  动态显示原理：原理上同一时刻只有一位LED是点亮的，但只要扫描的频率足够高(一般大于25Hz)，由于人眼的视觉暂留特性，直观上感觉却是连续点亮的，这就是常说的动态扫描显示。
                  动态扫描的频率有一定的要求，频率太低，LED将出现闪烁现象。如频率太高，由于每个LED点亮的时间太短，LED的亮度太低，所以一般均取几个ms左右为宜。
                  8.3 DG3000 动态显示头文件display_s.h
                  //----------------------------------------------------------
                  //程序作用：显示头文件display_s.h
                  //----------------------------------------------------------
                  #ifndef _display_
                  #define _display_
                  #include <intrins.h>
                  sbit SDA=P2^6; //定义显示管脚
                  sbit CLK=P2^7;
                  unsigned char data display_bit;
                  unsigned char code
                  led[20]={0xc0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e,0xbf,0x89,0x8C};
                  //定义段码
                  //延时程序
                  void delay(unsigned int k)
                  { unsigned int i,j;
                  for(i=0;i<k;i++)
                  for(j=0;j<100;j++);
                  }
                  //数据传输
                  void send(unsigned char a)
                  {
                  unsigned char i;
                  for(i=0;i<8;i++)
                  {
                  if(_crol_(a,i)&0x80)
                  SDA=1;
                  else
                  SDA=0;
                  CLK=0;
                  CLK=1;
                  }
                  }
                  //显示程序 8位LED数码管扫描
                  void display(unsigned char display_buffer[8])
                  {
                  unsigned char i,k;
                  display_bit=0xfe;
                  for(i=0;i<8;i++)
                  {
                  k=led[display_buffer[i］;
                  send(k);
                  P0=display_bit;
                  delay(0x01);
                  P0=0xff;
                  display_bit=_crol_(display_bit,1);
                  }
                  display_bit=0xfe;
                  8.4 8位数码管动态显示01234567（C51程序）
                  //----------------------------------------------------------
                  //程序作用：动态扫描显示01234567
                  //----------------------------------------------------------
                  #include<REG52.h>
                  #include<display_s.h> //调用显示头文件
                  main()
                  {
                  unsigned char
                  a[8]={0x0,0x1,0x2,0x3,0x4,0x5,0x6,0x7};//显示01234567
                  while(1)
                  {
                  display(a); //显示数据
                  }
                  }
                  8.5 8位数码管动态显示01234567（汇编）
                  ;----------------------------------------------------------
                  ;程序作用：8位数码管动态显示01234567（汇编）
                  ;----------------------------------------------------------
                  ;定义变量
                  DBUF DATA 40H ;显示缓冲区首址
                  SP_BT DATA 60H ;堆栈指针初值
                  ; LED 位选
                  LED_CS1 BIT P0.0
                  LED_CS2 BIT P0.1
                  LED_CS3 BIT P0.2
                  LED_CS4 BIT P0.3
                  LED_CS5 BIT P0.4
                  LED_CS6 BIT P0.5
                  LED_CS7 BIT P0.6
                  LED_CS8 BIT P0.7
                  ;4094接口
                  SDA_4094 BIT P2^6
                  CLK_4094 BIT P2^7
                  ORG 0000H
                  AJMP MAIN
                  ;-------------------------------
                  ORG 0030H
                  MAIN: MOV SP,#60H
                  MOV R0,#0FFH;单元清零
                  RES1: MOV @R0,#0
                  DJNZ R0,RES1
                  MOV DBUF,#00H;显示数据
                  MOV DBUF+1,#01H
                  MOV DBUF+2,#02H
                  MOV DBUF+3,#03H
                  MOV DBUF+4,#04H
                  MOV DBUF+5,#05H
                  MOV DBUF+6,#06H
                  MOV DBUF+7,#07H
                  SAMP1:
                  LCALL DIR ;调用显示
                  SJMP SAMP1
                  ;------------------------------------------------------
                  ;显示数据
                  ;-------------------------------------------------------
                  DIR:
                  ;显示程序
                  MOV DPTR,#TABLE
                  MOV A,DBUF
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS1 ;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS1 ;关闭显示
                  MOV A,DBUF+1
                  MOVC A,@A+DPTR
                  //ANL A,#7FH;加小数点
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS2;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS2;关闭显示
                  MOV A,DBUF+2
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS3 ;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS3 ;关闭显示
                  MOV A,DBUF+3
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS4;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS4;关闭显示
                  MOV A,DBUF+4
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS5 ;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS5 ;关闭显示
                  MOV A,DBUF+5
                  MOVC A,@A+DPTR
                  // ANL A,#7FH;加小数点
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS6;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS6;关闭显示
                  MOV A,DBUF+6
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS7 ;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS7 ;关闭显示
                  MOV A,DBUF+7
                  MOVC A,@A+DPTR
                  ACALL DISP_da ;送段码输出
                  CLR LED_CS8;选通第1位数码管
                  LCALL DELAY_4094
                  SETB LED_CS8;关闭显示
                  ;-------------------------------------
                  RET
                  TABLE: DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H ;0~9
                  DB 88H,83H,0C6H,0A1H,86H,8EH ;A~F
                  ;-------------------------延时子程序---------------------------------
                  DELAY_4094: MOV R4,#2 ;延时程序3，精确延时1000微秒
                  D_4094:MOV R5,#248
                  DJNZ R5,$
                  DJNZ R4,D_4094
                  RET
                  DISP_DA:
                  MOV R3,#08H
                  DUP: RLC A
                  MOV SDA_4094,C
                  CLR CLK_4094
                  SETB CLK_4094
                  DJNZ R3,DUP
                  RET
                  END