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最新推荐文章于 2022-11-27 12:18:13 发布

原创最新推荐文章于 2022-11-27 12:18:13 发布 · 238 阅读

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本文介绍了一种基于51单片机的I2C通信协议实现方法，详细展示了I2C开始、停止信号的发送，以及数据的写入与读取过程。该实现方式适用于简单的I2C设备间通信。

#include<reg52.h>
#include<intrins.h>

#define I2CDelay() {_nop_();_nop_();_nop_();_nop_();}
sbit I2C_SCL = P2^0;
sbit I2C_SDA = P2^1;

void I2CStart()
{
I2C_SDA = 1;
I2C_SCL = 1;
I2CDelay();
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 0;
}

void I2CStop()
{
I2C_SCL = 0;
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SDA = 1;
I2CDelay();
}

bit I2CWrite(unsigned char dat)
{
bit ack;
unsigned char mask;

for(mask=0x80;mask!=0;mask>>=1)
{
if((mask&dat) == 0)
I2C_SDA = 0;
else
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
ack = I2C_SDA;
I2CDelay();
I2C_SCL = 0;

return (~ack);
}

unsigned char I2CReadNAK()
{
unsigned char mask;
unsigned char dat;

I2C_SDA = 1;
for(mask=0x80;mask!=0;mask>>=1)
{
I2CDelay();
I2C_SCL = 1;
if(I2C_SDA == 0)
dat &= ~mask;
else
dat |= mask;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 1;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;

return dat;
}

unsigned char I2CReadACK()
{
unsigned char mask;
unsigned char dat;

I2C_SDA = 1;
for(mask=0x80;mask!=0;mask>>=1)
{
I2CDelay();
I2C_SCL = 1;
if(I2C_SDA == 0)
dat &= ~mask;
else
dat |= mask;
I2CDelay();
I2C_SCL = 0;
}
I2C_SDA = 0;
I2CDelay();
I2C_SCL = 1;
I2CDelay();
I2C_SCL = 0;

return dat;
}