/*
下面给出STM32通过GPIO模拟I2C读写EEPROM程序
*/
#define SCL_H
GPIOB->BSRR = GPIO_Pin_6
#define SLC_L
GPOIB->BRR = GPIO_Pin_6
#define
SDA_H
GPIOB->BSRR
= GPIO_Pin_7
#define SDA_L
GPIOB->BRR
= GPIO_Pin_7
#define
SCL_read GPIOB-IDR & GPIO_Pin_6
#define SDA_read GPIOB->IDR & GPIO_Pin_7
#define I2C_PageSize 8
void I2C_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*Configure I2C1 Pins:SCL and SDA*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 |GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_50Hz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPOI_Init(GPIOB,&GPIO_InitStructure);
}
void I2C_delay(void)
{
u8 i=100; //设置通信速度
while(i)
{
i--;
}
}
bool I2C_Start(void)
{
SDA_H;
SCL_H;
I2C_delay();
if(!SDA_read) return FALSE; //SDA线为低电平总线忙,退出
SDA_L;
I2C_delay();
if(SDA_read) return FALSE; //SDA线为高电平则总线出错,退出
SDA_L;
I2C_delay();
return TRUE;
}
void I2C_Stop(void)
{
SCL_L;
I2C_delay();
SDA_L;
I2C_delay();
SCL_H;
I2C_delay();
SDA_H;
I2C_delay();
}
void I2C_Ack(void)
{
SCL_L;
I2C_delay();
SDA_L;
I2C_delay();
SCL_H;
I2C_delay();
SCL_L;
I2C_delay();
}
void I2C_NoAck(void)
{
SCL_L;
I2C_delay();
SDA_H;
I2C_delay();
SCL_H;
I2C_delay();
SCL_L;
I2C_delay();
}
bool I2C_WaitAck(void) //返回为:-1有ACK, =0 无ACK
{
SCL_L;
I2C_delay();
SDA_H;
I2C_delay();
SCL_H;
I2C_delay();
if(SDA_read)
{
SCL_L;
return FALSE;
}
SCL_L;
return TRUE;
}
void I2C_SendByte(u8 SendByte) //数据从高位到低位
{
u8 i=8;
while(i--)
{
SCL_L;
I2C_delay();
if(SendByte & 0x80)
SDA_H;
else
SDA_L;
SendByte <<= 1;
I2C_delay();
SCL_H;
I2C_delay();
}
SCL_L;
}
void I2C_ReceiveByte(void) //数据从高位到低位
{
u8 i=8;
u8 ReceiveByte = 0;
SDA_H;
while(i--)
{
ReceiveByte <<= 1;
SCL_L;
I2C_delay();
SCL_H;
I2C_delay();
if(SDA_read)
{
ReceiveByte|=0x01;
}
}
SCL_L;
return ReceiveByte;
}
//写入1字节数据 (代写入数据,待写入地址,器件类型)
bool I2C_WirteByte(u8 SendByte,u16 WriteAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((WriteAddress & 0x0700)>>7)|DeviceAddress & 0xFFFE);
//设置高起始地址 + 器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(WriteAddress & 0x00FF)); //设置低起始地址
I2C_WaitAck();
I2C_SendByte(SendByte);
I2C_WaitAck();
I2C_Stop();
//注意:因为这里要等待EERPOM写完成,可以采用查询 或延时方式(10ms)
//Systick_Delay_1ms(10);
return TRUE;
}
//注意不能跨页写
//写入1串数据(待写入数组地址,待写入长度,待写入地址,器件类型)
bool I2C_BufferWrite(u8 *pBuffer,u8 length,u16 WriteAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((WriteAddress & 0x0700)>>7)|DeviceAddress & 0xFFFE);
//设置高起始地址 + 器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(WriteAddress & 0x00FF)); //设置低起始地址
I2C_WaitAck();
while(length--)
{
I2C_SendByte(*pBuffer);
I2C_WaitAck();
pBuffer++;
}
I2C_Stop();
//注意:因为这里要等待EERPOM写完成,可以采用查询 或延时方式(10ms)
//Systick_Delay_1ms(10);
return TRUE;
}
//跨页写入1串数据(待写入数组地址,待写入长度,待写入地址,器件类型)
void I2C_PageWrite(u8 *pBuffer,u8 length,u16 WriteAddress,u8 DeviceAddress )
{
u8 NumOfPage=0,NumOfSingle=0,Addr=0,count=0;
Addr = WriteAddress%I2C_PageSize; //写入地址是开始页的第几页
count = I2C_PageSize - Addr; //在开始页要写入的个数
NumOfPage = length/I2C_PageSize; //要写入的页数
NumOfSingle = length%I2C_PageSize; //不足一页的个数
if(Addr == 0) //写入地址是页开始
{
if(NumOfPage == 0) //数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress); //写少于一页的数据
}
else //数据大于一页
{
while(NumOfPage) //要写入的页数
{
I2C_BufferWrite(pBuffer,I2C_PageSize,WriteAddress,DeviceAddress);//写一页的数据
WriteAddress += I2C_PageSize;
pBuffer += I2C_PageSize;
NumOfPage--;
Systick_Delay_1ms(10);
}
if(NumOfSingle!=0) //剩余数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
Systick_Delay_1ms(10);
}
}
}
else //写入的数据不是页的开始
{
if(NumOfPage == 0) //数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
}
else //数据大于等于一页
{
length = count;
NumOfPage = length / I2C_PageSize; //重新计算要写入的页数
NumOfSingle = length % I2C_PageSize;
//重新计算不足一页的个数
if(count!=0)
{
I2C_BufferWrite(pBuffer,count,WriteAddress,DeviceAddress);
//将开始的空间写满一页
WriteAddress += count;
pBuffer +=count;
}
while(NumOfPage--) //要写入的页数
{
I2C_BufferWrite(pBuffer,I2C_PageSize,WriteAddress,DeviceAddress); //写一页的数据
WriteAddress += I2C_PageSize;
pBuffer += I2C_PageSize;
}
if(NumOfSingle != 0) //剩余数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
}
}
}
}
//读出1串数据(存放读出数据,待读出长度,带读出地址,器件类型)
bool I2C_ReadByte(u8 *pBuffer,u8 length,u16 ReadAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((ReadAddress&0x0700)>>7)|DeviceAddress&0xFFFE);//设置高起始地址+器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(ReadAddress & 0x00FF));//设置低起始地址
I2C_WaitAck();
I2C_Start();
I2C_SendByte(((ReadAddress&0x0700)>>7)|DeviceAddress&0x0001);
I2C_WaitAck();
while(length)
{
*pBuffer = I2C_ReceiveByte();
if(length==1) I2C_NoAck();
else I2C_Ack();
pBuffer++;
length--;
}
I2C_Stop;
return TRUE;
}
/*
下面给出STM32通过GPIO模拟I2C读写EEPROM程序
*/
#define SCL_H GPIOB->BSRR = GPIO_Pin_6
#define SLC_L GPOIB->BRR = GPIO_Pin_6
#define SDA_H GPIOB->BSRR = GPIO_Pin_7
#define SDA_L GPIOB->BRR = GPIO_Pin_7
#define SCL_read GPIOB-IDR & GPIO_Pin_6
#define SDA_read GPIOB->IDR & GPIO_Pin_7
#define I2C_PageSize 8
void I2C_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*Configure I2C1 Pins:SCL and SDA*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 |GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_50Hz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPOI_Init(GPIOB,&GPIO_InitStructure);
}
void I2C_delay(void)
{
u8 i=100; //设置通信速度
while(i)
{
i--;
}
}
bool I2C_Start(void)
{
SDA_H;
SCL_H;
I2C_delay();
if(!SDA_read) return FALSE; //SDA线为低电平总线忙,退出
SDA_L;
I2C_delay();
if(SDA_read) return FALSE; //SDA线为高电平则总线出错,退出
SDA_L;
I2C_delay();
return TRUE;
}
void I2C_Stop(void)
{
SCL_L;
I2C_delay();
SDA_L;
I2C_delay();
SCL_H;
I2C_delay();
SDA_H;
I2C_delay();
}
void I2C_Ack(void)
{
SCL_L;
I2C_delay();
SDA_L;
I2C_delay();
SCL_H;
I2C_delay();
SCL_L;
I2C_delay();
}
void I2C_NoAck(void)
{
SCL_L;
I2C_delay();
SDA_H;
I2C_delay();
SCL_H;
I2C_delay();
SCL_L;
I2C_delay();
}
bool I2C_WaitAck(void) //返回为:-1有ACK, =0 无ACK
{
SCL_L;
I2C_delay();
SDA_H;
I2C_delay();
SCL_H;
I2C_delay();
if(SDA_read)
{
SCL_L;
return FALSE;
}
SCL_L;
return TRUE;
}
void I2C_SendByte(u8 SendByte) //数据从高位到低位
{
u8 i=8;
while(i--)
{
SCL_L;
I2C_delay();
if(SendByte & 0x80)
SDA_H;
else
SDA_L;
SendByte <<= 1;
I2C_delay();
SCL_H;
I2C_delay();
}
SCL_L;
}
void I2C_ReceiveByte(void) //数据从高位到低位
{
u8 i=8;
u8 ReceiveByte = 0;
SDA_H;
while(i--)
{
ReceiveByte <<= 1;
SCL_L;
I2C_delay();
SCL_H;
I2C_delay();
if(SDA_read)
{
ReceiveByte|=0x01;
}
}
SCL_L;
return ReceiveByte;
}
//写入1字节数据 (代写入数据,待写入地址,器件类型)
bool I2C_WirteByte(u8 SendByte,u16 WriteAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((WriteAddress & 0x0700)>>7)|DeviceAddress & 0xFFFE); //设置高起始地址 + 器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(WriteAddress & 0x00FF)); //设置低起始地址
I2C_WaitAck();
I2C_SendByte(SendByte);
I2C_WaitAck();
I2C_Stop();
//注意:因为这里要等待EERPOM写完成,可以采用查询 或延时方式(10ms)
//Systick_Delay_1ms(10);
return TRUE;
}
//注意不能跨页写
//写入1串数据(待写入数组地址,待写入长度,待写入地址,器件类型)
bool I2C_BufferWrite(u8 *pBuffer,u8 length,u16 WriteAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((WriteAddress & 0x0700)>>7)|DeviceAddress & 0xFFFE); //设置高起始地址 + 器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(WriteAddress & 0x00FF)); //设置低起始地址
I2C_WaitAck();
while(length--)
{
I2C_SendByte(*pBuffer);
I2C_WaitAck();
pBuffer++;
}
I2C_Stop();
//注意:因为这里要等待EERPOM写完成,可以采用查询 或延时方式(10ms)
//Systick_Delay_1ms(10);
return TRUE;
}
//跨页写入1串数据(待写入数组地址,待写入长度,待写入地址,器件类型)
void I2C_PageWrite(u8 *pBuffer,u8 length,u16 WriteAddress,u8 DeviceAddress )
{
u8 NumOfPage=0,NumOfSingle=0,Addr=0,count=0;
Addr = WriteAddress%I2C_PageSize; //写入地址是开始页的第几页
count = I2C_PageSize - Addr; //在开始页要写入的个数
NumOfPage = length/I2C_PageSize; //要写入的页数
NumOfSingle = length%I2C_PageSize; //不足一页的个数
if(Addr == 0) //写入地址是页开始
{
if(NumOfPage == 0) //数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress); //写少于一页的数据
}
else //数据大于一页
{
while(NumOfPage) //要写入的页数
{
I2C_BufferWrite(pBuffer,I2C_PageSize,WriteAddress,DeviceAddress);//写一页的数据
WriteAddress += I2C_PageSize;
pBuffer += I2C_PageSize;
NumOfPage--;
Systick_Delay_1ms(10);
}
if(NumOfSingle!=0) //剩余数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
Systick_Delay_1ms(10);
}
}
}
else //写入的数据不是页的开始
{
if(NumOfPage == 0) //数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
}
else //数据大于等于一页
{
length = count;
NumOfPage = length / I2C_PageSize; //重新计算要写入的页数
NumOfSingle = length % I2C_PageSize;
//重新计算不足一页的个数
if(count!=0)
{
I2C_BufferWrite(pBuffer,count,WriteAddress,DeviceAddress);
//将开始的空间写满一页
WriteAddress += count;
pBuffer +=count;
}
while(NumOfPage--) //要写入的页数
{
I2C_BufferWrite(pBuffer,I2C_PageSize,WriteAddress,DeviceAddress); //写一页的数据
WriteAddress += I2C_PageSize;
pBuffer += I2C_PageSize;
}
if(NumOfSingle != 0) //剩余数据小于一页
{
I2C_BufferWrite(pBuffer,NumOfSingle,WriteAddress,DeviceAddress);
//写少于一页的数据
}
}
}
}
//读出1串数据(存放读出数据,待读出长度,带读出地址,器件类型)
bool I2C_ReadByte(u8 *pBuffer,u8 length,u16 ReadAddress,u8 DeviceAddress)
{
if(!I2C_Start()) return FALSE;
I2C_SendByte(((ReadAddress&0x0700)>>7)|DeviceAddress&0xFFFE);//设置高起始地址+器件地址
if(!I2C_WaitAck())
{
I2C_Stop();
return FALSE;
}
I2C_SendByte((u8)(ReadAddress & 0x00FF));//设置低起始地址
I2C_WaitAck();
I2C_Start();
I2C_SendByte(((ReadAddress&0x0700)>>7)|DeviceAddress&0x0001);
I2C_WaitAck();
while(length)
{
*pBuffer = I2C_ReceiveByte();
if(length==1) I2C_NoAck();
else I2C_Ack();
pBuffer++;
length--;
}
I2C_Stop;
return TRUE;
}