写一段STM32 IIC的C语言

以下是一个简单的STM32 IIC的C语言例程，可以通过IIC总线连接到其他IIC设备进行数据传输。

#include "stm32f10x.h"

#define SLAVE_ADDRESS 0x50

void IIC_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    I2C_InitTypeDef I2C_InitStructure;
    
    // Enable GPIOB and I2C1 clocks
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
    
    // Configure GPIOB pins as I2C alternate function
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
    
    // Configure I2C1
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0x00;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStructure.I2C_ClockSpeed = 100000;
    I2C_Init(I2C1, &I2C_InitStructure);
    I2C_Cmd(I2C1, ENABLE);
}

void IIC_write(uint8_t addr, uint8_t* buffer, uint16_t length)
{
    uint16_t i = 0;
    
    // Wait for I2C ready
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
    
    // Generate start condition
    I2C_GenerateSTART(I2C1, ENABLE);
    
    // Wait for start condition generated
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
    
    // Send slave address with write bit
    I2C_Send7bitAddress(I2C1, addr, I2C_Direction_Transmitter);
    
    // Wait for address sent
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    
    // Send data
    for(i=0; i<length; i++)
    {
        I2C_SendData(I2C1, buffer[i]);
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    }
    
    // Generate stop condition
    I2C_GenerateSTOP(I2C1, ENABLE);
}

void IIC_read(uint8_t addr, uint8_t* buffer, uint16_t length)
{
    uint16_t i = 0;
    
    // Wait for I2C ready
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
    
    // Generate start condition
    I2C_GenerateSTART(I2C1, ENABLE);
    
    // Wait for start condition generated
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
    
    // Send slave address with read bit
    I2C_Send7bitAddress(I2C1, addr, I2C_Direction_Receiver);
    
    // Wait for address sent
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
    
    // Receive data
    for(i=0; i<length-1; i++)
    {
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
        buffer[i] = I2C_ReceiveData(I2C1);
    }
    
    // Disable ACK on last byte
    I2C_AcknowledgeConfig(I2C1, DISABLE);
    
    // Receive last byte and generate stop condition
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
    buffer[i] = I2C_ReceiveData(I2C1);
    I2C_GenerateSTOP(I2C1, ENABLE);
    
    // Enable ACK for next transaction
    I2C_AcknowledgeConfig(I2C1, ENABLE);
}

int main(void)
{
    uint8_t tx_buffer[10] = {0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x11, 0x22};
    uint8_t rx_buffer[10];
    
    IIC_init();
    
    // Write data to slave device
    IIC_write(SLAVE_ADDRESS, tx_buffer, 10);
    
    // Read data from slave device
    IIC_read(SLAVE_ADDRESS, rx_buffer, 10);
    
    while(1);
}