若要使用STM32F0操作硬件I2C外设，可使用下面的步骤。
1、配置GPIO引脚功能
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_1);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_1);
2、初始化I2C外设
I2C_InitTypeDef I2C_InitStructure;
RCC_I2CCLKConfig(RCC_I2C1CLK_SYSCLK);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable;
I2C_InitStructure.I2C_DigitalFilter = 0x01;
I2C_InitStructure.I2C_OwnAddress1 = 0x00;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_Timing = 0x30E32E44;
I2C_Init(I2C1, &I2C_InitStructure);
I2C_Cmd(I2C1, ENABLE);
3、调用I2C的外设库函数进行读写I2C
我采用的是查询方式
主要使用的库函数有：
（A）void I2C_TransferHandling(I2C_TypeDef* I2Cx, uint16_t Address, uint8_t Number_Bytes, uint32_t ReloadEndMode, uint32_t StartStopMode)
（B）uint8_t I2C_ReceiveData ( I2C_TypeDef * I2Cx )
（C）void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data)
详细说明可看标准外设库帮助文档。
（1）I2C设备读数据程序段
/**
* @brief 从I2C1总线上的某一器件的某一起始地址中读取一定字节的数据到数组中
* @param driver_Addr：I2C器件地址
* @param start_Addr：起始字节地址
* @param number_Bytes：要读取的字节数量（小于一页）
* @param read_Buffer：存放读取数据的数组指针
* @retval 是否读取成功
*/
I2C_Status I2C1_Read_NBytes(uint8_t driver_Addr, uint8_t start_Addr, uint8_t number_Bytes, uint8_t *read_Buffer)
{
uint8_t read_Num;
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_TransferHandling(I2C1, driver_Addr, 1, I2C_SoftEnd_Mode, I2C_Generate_Start_Write);
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_SendData(I2C1, start_Addr);
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TC) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_TransferHandling(I2C1, driver_Addr, number_Bytes, I2C_AutoEnd_Mode, I2C_Generate_Start_Read);
for(read_Num = 0; read_Num < number_Bytes; read_Num++)
{
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_RXNE) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
read_Buffer[read_Num] = I2C_ReceiveData(I2C1);
}
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
return I2C_OK;
}
（2）I2C设备写数据程序段
/**
* @brief 从I2C1的总线上的某一器件的某一起始地址中读取一定字节的数据到数组中
* @param driver_Addr：I2C器件地址
* @param start_Addr：起始字节地址
* @param number_Bytes：要读取的字节数量（小于一页）
* @param write_Buffer：存放读取数据的数组指针
* @retval 是否读取成功
*/
I2C_Status I2C1_Write_NBytes(uint8_t driver_Addr, uint8_t start_Addr, uint8_t number_Bytes, uint8_t *write_Buffer)
{
uint8_t write_Num;
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY) != RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_TransferHandling(I2C1, driver_Addr, 1, I2C_Reload_Mode, I2C_Generate_Start_Write);
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_SendData(I2C1, start_Addr);
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TCR) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_TransferHandling(I2C1, driver_Addr, number_Bytes, I2C_AutoEnd_Mode, I2C_No_StartStop);
for(write_Num = 0; write_Num < number_Bytes; write_Num++)
{
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_TXIS) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
I2C_SendData(I2C1, write_Buffer[write_Num]);
}
I2C_Timeout = I2C_TIMEOUT;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF) == RESET)
{
if((I2C_Timeout--) == 0)
{
return I2C_FAIL;
}
}
return I2C_OK;
}
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