PCF8591实现AD转换程序.doc

PCF8591实现AD转换程序#includesbit SCL=P21;sbit SDA=P20;sbit dula=P26;sbit wela=P27;unsigned char code table=0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71;void delay()int i=4;while(i-);void delay_s()unsigned char a,b; for(b=3;b0;b-)for(a=100;a0;a-);void display(int dd)dula=1;P0=tabledd/100;dula=0;delay_s();P0=0xff;wela=1;P0=0xfe;wela=0;delay_s();wela=1;P0=0xff;wela=0;dula=1;P0=0x80;dula=0;delay_s();P0=0xff;wela=1;P0=0xfe;wela=0;delay_s();wela=1;P0=0xff;wela=0;dula=1;P0=tabledd%100/10;dula=0;delay_s();P0=0xff;wela=1;P0=0xfd;wela=0;delay_s();wela=1;P0=0xff;wela=0;dula=1;P0=tabledd%10;dula=0;delay_s();P0=0xff;wela=1;P0=0xfb;wela=0;delay_s();wela=1;P0=0xff;wela=0;/写iic总线的几个重要函数void initIIC()SCL=1;delay();SDA=1;delay();void start()SCL=1;delay();SDA=1;delay();SDA=0;delay();void respons()unsigned char i;SCL=1;delay();while(SDA=1)&i255) i+;SCL=0;delay();void stop()SCL=1;delay();SDA=0;delay();SDA=1;delay();void writebyte(unsigned char date)unsigned char temp,i;temp=date;for(i=0;i8;i+)temp=temp1;SCL=0;delay();SDA=CY;delay();SCL=1;delay();SCL=0;delay();SDA=1;delay();unsigned char readbyte()unsigned char i,k;SCL=0;delay();SDA=1;for(i=0;i9;i+)SCL=1;delay();k=(k1)|SDA;SCL=0;delay();delay();return k;/发送数据给芯片void send(unsigned char address, unsigned char date)start();writebyte(0x90);respons();writebyte(address);respons();writebyte(date);respons();stop();/从芯片独处数据unsigned char read(unsigned char address)unsigned char temp;start();writebyte(0x90);respons();writebyte(address);respons();start();writebyte(0x91);temp=readbyte();return temp;void main()int temp