IIC.zip_IIC_PYB_iic 串口显示_串口at24c02

#include "i2c.h" void delay(void) // 10us { unsigned char a,b; for(b=1;b>0;b--) for(a=2;a>0;a--); } void I2cStart() //起始信号 { SDA=1; delay(); SCL=1; delay(); SDA=0; delay(); SCL=0; delay(); } void I2cStop() //终止信号 { SDA=0; delay(); SCL=1; delay(); SDA=1; delay(); } unsigned char I2cSendByte(unsigned char dat) //发送函数 { unsigned char a=0,b; for(a=0;a<8;a++) { SDA=dat>>7; dat=dat<<1; delay(); SCL=1; //高电平数据保持稳定 delay(); SCL=0; //低电平数据可以改变 delay(); } SDA=1; //数据线和时钟线释放出来，等待从机应答 delay(); SCL=1; while(SDA) { b++; //等待一段时间出去 if(b>200) { SCL=0; delay(); return 0;//发送失败返回0 } } SCL=0; delay(); return 1;//发送成功返回1 } unsigned char I2cReadByte() { unsigned char a=0,dat=0; SDA=1; //拉高，等待数据线数据 delay(); for(a=0;a<8;a++) { SCL=1; // 高电平数据保持稳定 delay(); dat<<=1; dat|=SDA; delay(); SCL=0; delay(); } return dat; } void At24c02Write(unsigned char addr,unsigned char dat) { I2cStart(); I2cSendByte(0xa0); I2cSendByte(addr); I2cSendByte(dat); I2cStop(); } unsigned char At24c02Read(unsigned char addr) { unsigned char num; I2cStart(); I2cSendByte(0xa0); I2cSendByte(addr); I2cStart(); I2cSendByte(0xa1); num=I2cReadByte(); I2cStop(); return num; }