IIC总线程序.doc

#include#define uchar unsigned char#define uint unsigned intsbit scl=P15;sbit sda=P36;void delay() /短延时 ; ; ; ;void delay1(uchar x) /长延时 uint i; for(i=0;ix;i+);void init()/ 初始化 使scl和sda都置1 scl=1; delay(); sda=1; delay();void start()/ 开始 scl在高电平状态，sda有个下降信号 sda=1; delay(); scl=1; delay(); sda=0; delay(); scl=0; delay();void stop() /终止 scl在高电平状态，sda有个低到高的跳变 sda=0; delay(); scl=1; delay(); sda=1; delay();void write_byte(uchar date) /写数据 uchar i,temp; temp=date; for(i=0;i8;i+) /写8次数据 temp=temp1; /左移1位 scl=0; delay(); sda=CY; /最高位给CY delay(); scl=1; delay(); scl=0; delay(); sda=1; delay();void respons() / 应答 uchar i=0; scl=1; /在高电平 delay(); while(sda=1)&(i255)i+; /sda=1,则没有收到应答信号，且受时间限制 scl=0; /时钟结束 delay();uchar read_byte() / 读数据 uchar i,j,k; scl=0; delay(); sda=1; /释放数据总线 delay(); for(i=0;i8;i+) scl=1; /scl=1的时候数据才稳定 delay(); if(sda=1)j=1; else j=0; k=(k1)|j; /k左移，后最低位为0，与j或运算，就把j写到了k的最低位 scl=0; /置低，完成一个时钟 delay(); delay(); return k;void write_add(uchar address,uchar info) /定义地址address，数据date start(); write_byte(0xa0); respons(); write_byte(address); respons(); write_byte(info); respons(); stop(); delay1(50);uchar read_add(uchar address)/读取数据，有返回值 uchar i; start(); write_byte(0xa0); respons(); write_byte(address); respons(); start(); write_byte(0xa1); respons(); i=read_byte(); stop(); delay1(10); return i ;void main() init(); write_add(0xaa,0xfe