I2C.zip_读I2C

#include <STC12C5A.h> #include <intrins.h> #include <math.h> #include <stdio.h> sbit scl=P3^6; sbit sda=P3^7; void init_uart() { SM0=0; SM1=1; BRT=0x98; //300bps AUXR=0x11; ES=1; EA=1; REN=1; } void send_char(unsigned char txd) { ES = 0; TI = 0; SBUF = txd; while(!TI); // 等特数据传送 TI = 0; // 清除数据传送标志 ES=1; } void send_str(unsigned char *str) // 传送字串 { unsigned char i = 0; for(i=0; str[i]!='\0';i++) { send_char(str[i]); } } //*************24c04*******************// void delay1(unsigned char x) { unsigned int i; for(i=0;i<x;i++) {;;} } void flash() { ; ; } void x24c04_init() //24c04初始化子程序 { scl=1; flash(); sda=1; flash(); } void start() //启动I2C总线 { sda=1; flash(); scl=1; flash(); sda=0; flash(); scl=0; flash(); } void stop() //停止I2C总线 { sda=0; flash(); scl=1; flash(); sda=1; flash(); } void writex(unsigned char j) //写一个字节 { unsigned char i,temp; temp=j; for (i=0;i<8;i++) { temp=temp<<1; scl=0; flash(); sda=CY; flash(); scl=1; flash(); } scl=0; flash(); sda=1; flash(); } unsigned char readx() //读一个字节 { unsigned char i,j,k=0; scl=0; flash(); sda=1; for (i=0;i<8;i++) { flash(); scl=1; flash(); if (sda==1) j=1; else j=0; k=(k<<1)|j; scl=0; } flash(); return(k); } void clock() //I2C总线时钟 { unsigned char i=0; scl=1; flash(); while ((sda==1)&&(i<255))i++; scl=0; flash(); } /*******从24c02的地址address中读取一个字节数据******/ unsigned char x24c04_read(unsigned char address) { unsigned char i; start(); writex(0xa0); clock(); writex(address); clock(); start(); writex(0xa1); clock(); i=readx(); stop(); delay1(10); return(i); } /*****向24c02的address地址中写入一字节数据info*******/ void x24c04_write(unsigned char address,unsigned char info) { EA=0; start(); writex(0xa0); clock(); writex(address); clock(); writex(info); clock(); stop(); EA=1; delay1(50); } void main() { unsigned char temp=0,im; init_uart(); x24c04_init(); x24c04_write(121,0x80); for(im=0;im<4;im++) { temp=x24c04_read(121); delay1(50); } while(1) { send_char(temp); } }