电压表实验（AD转换）

 1 /*电压表 精确到小数点后面三位*/

 2 /*连线：电位器接IN0，AD_CS接CS0,CS1接KEY/LED_CS*/

 3 #include

 4 typedef unsigned char uchar;

 5 xdata uchar LED_CS _at_ 0x9000;

 6 xdata uchar LED_OUTSEG _at_ 0x9004;

 7 xdata uchar LED_OUTBIT _at_ 0x9002;

 8 

 9 xdata uchar AD_CS _at_ 0x8000;

10 xdata uchar AD_MODE _at_ 0x8003;

11 

12 code unsigned char LEDMAP[] = {  // 八段管显示码

13   0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,

14   0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71

15 };

16 code unsigned char LEDWED[] = {0x20,0x10,0x08,0x04,0x02,0x01};

17 int num[6];

18 void delay(int ms)

19 {

20  int i,j;

21  for(i=0;i

22     for(j=0;j<14;j++)

23          ;

24 }

25 void adf()

26 {

27  AD_CS = 0;

28  delay(10);

29 }

30 void main()

31 {

32  int led_c=0;

33  unsigned char temp;

34  AD_MODE = 0x82;

35  AD_CS = 0;

36  while(1)

37  {

38   adf();

39   delay(10);

40   num[0] = AD_CS*5/256;

41   num[1] = AD_CS*5%256*10/256;

42   num[2] = AD_CS*5%256*10%256*10/256;

43   num[3] = AD_CS*5%256*10%256*10%256*10/256;

44   temp = LEDMAP[num[led_c]];

45   if(led_c == 0)

46            temp = temp|0x80;

47   LED_OUTBIT = LEDWED[led_c];

48   LED_OUTSEG = temp;

49   led_c = (led_c+1)%4;

50   delay(10);

51  }

52 }