AD7894驱动

  1 #include <htc.h>
  2 //#define FOSC_HS 0xFFFE
  3  
  4 #define _XTAL_FREQ 20000000  //20MHz晶振
  5  
  6 #define CONVST RA0
  7 #define BUSY   RA1
  8 #define SDATA  RA2
  9 #define SCLK   RA3
 10 #define TXD    RB1
 11  
 12 //////////////Prototypes////////////////
 13  
 14 unsigned char readfromad7894(void);
 15 void sendbyte(unsigned char value);
 16 void delay(unsigned char count);
 17  
 18 ///////////////////////////////////////
 19  
 20  
 21 unsigned char readfromad7894(void)
 22 {
 23  
 24     char i;
 25     unsigned int X;
 26     CONVST=0;
 27     delay(100);
 28     CONVST=1;
 29     delay(100);
 30     X=0;
 31     SCLK=0;
 32     for(i=0;i<16;i++)
 33       {
 34  
 35         SCLK=1;
 36         delay(100);
 37            X=X+1;
 38            SCLK=0;
 39         delay(100);
 40         TXD=SDATA;
 41        
 42 }
 43  
 44     delay(100);
 45   return(X);
 46  
 47 }
 48  
 49 /*void sendbyte(unsigned char value)
 50 {
 51  
 52     unsigned char j;
 53     TXD=0;        //先传高位
 54     delay(100);
 55     for(j=0;j<8;j++)
 56     {
 57  
 58         TXD=(value&0x01); //再传低位
 59         delay(100);
 60         value>>=1;
 61      
 62 }
 63     TXD=1;  //发送结束标志位
 64     delay(100);
 65  
 66 }*/
 67  
 68 ////////////////////Main////////////////////
 69  
 70 void main(void)
 71 {
 72  
 73     TRISA=0xF6;       //RA0,RA3 输出,RA1,RA2 输入
 74     TRISB=0x00;       //RB 输出
 75     OPTION_REG=0x07;  //TMR0
 76     CONVST=1;
 77     TXD=0;
 78     delay(100);
 79     unsigned char Y;
 80     ADCON1=0x06;
 81     CONVST=1;  
 82     delay(100);
 83     SCLK=0;
 84     delay(100);
 85     while(1)
 86     {
 87  
 88       //TXD=0;
 89       Y=readfromad7894();
 90       //NOP();
 91       //sendbyte(Y);
 92       //sendbyte(Y>>8);
 93       delay(100);
 94      
 95 }
 96  
 97 }
 98  
 99 /////////////////Delay//////////////////
100  
101 void delay(unsigned char count)
102 {
103  
104     unsigned char k;
105     for(k=0;k<count;k++);
106     NOP();
107  
108 }