从图中可以看到，如果进行一个写的操作，也是要先发送一个启动操作，然后发送设备地址，接着发送字节地址，最后发送数据，然后停止。Tips:先发送高位，再发送低位

        设备地址（Device Address）：IIC总线上的地址。

A2，A1，A0看设备接线的电平，若A1接低电平，则为0； 

第八位（R/W）为0时，为写操作；第八位为1时，为读操作。

接下来的代码中，Device Address设为0xA0；

发送字节代码

void IIC_Send_Byte(unsigned char data)
{
	SDA_OUT();
	
	for(int i=0;i<8;i++)
	{
		if(data & 0x80)
		{
			IIC_SDA_H;
		}
		else
		{
			IIC_SDA_L;
		}
		IIC_SCL_L;
		IIC_SCL_H;
		
		IIC_SCL_L;
		data=data<<1;
	}
}

 写单个字节代码

        可以看一下第一个图，一一对应代码，就简单易懂了。

void IIC_Write_Byte(unsigned int addr,unsigned char data)
{
	IIC_START();
	
	IIC_Send_Byte(0xA0);
	
	while(IIC_Wait_ACK());
	
	IIC_Send_Byte(addr);
	
	while(IIC_Wait_ACK());
	
	IIC_Send_Byte(data);
	
	while(IIC_Wait_ACK());
	
	IIC_STOP();
	
}

写多个字节代码

这里假设发送size个字节 

void IIC_Write_Page(unsigned int addr,unsigned char *data,unsigned int size)
{
	IIC_START();
	
	IIC_Send_Byte(0xA0);
	
	while(IIC_Wait_ACK());
	
	IIC_Send_Byte(addr);
	
	while(IIC_Wait_ACK());
	while(size--)
	{
		IIC_Send_Byte(*data);
		while(IIC_Wait_ACK());
		data++;
		addr++;
	}
	IIC_STOP();
}

写任意长度字节

void AT24C02_Wirte(unsigned char addr,unsigned char *data,unsigned int size)
{
	while(size--)
	{
		IIC_Write_Byte(addr,*data);
		data++;
		addr++;
	}
}

 读当前地址的字节代码

unsigned char IIC_Receive_Byte(void)
{
	unsigned int i;
	unsigned char data;
	SDA_IN();
	for(i = 0; i < 8; i++)
	{
		IIC_SCL_L;
		IIC_SCL_H;
		data <<= 1;
		if(Read_SDA)
			data++;
		IIC_SCL_L;			
	}
	return data;
}

 随机读代码（读出特定地址的值）

unsigned char IIC_Read_Byte(unsigned char addr)
{
	unsigned char data;
	//假写beginning
	IIC_START();
	IIC_Send_Byte(0xA0);
	while(IIC_Wait_ACK());
	IIC_Send_Byte(addr);
	while(IIC_Wait_ACK());
	//假写end
	IIC_START();
	IIC_Send_Byte(0xA1);
	while(IIC_Wait_ACK());
	data = IIC_Receive_Byte();
	IIC_STOP();
	
	return data;
}

 顺序读代码

void AT24C02_Read_Buf(unsigned char addr, unsigned char *data, unsigned int size)
{
    //假写beginning
	IIC_START();
	IIC_Send_Byte(0xA0);
	while(IIC_Wait_ACK());
	IIC_Send_Byte(addr);
	while(IIC_Wait_ACK());
	//假写end
	IIC_START();
	IIC_Send_Byte(0xA1);
	while(IIC_Wait_ACK());
	while(size > 1)
	{
		*data = IIC_Receive_Byte();
		IIC_ACK();
		data++;
		addr++;
		size--;
	}
	
	*data = IIC_Receive_Byte();
	IIC_STOP();
}