C语言写stm32软件模拟IIC从机

以下是一个简单的C语言程序，用于在STM32上模拟IIC从机：

#include "stm32f4xx.h"

#define I2C_SLAVE_ADDRESS 0x50

void I2C_Configuration(void);
void I2C_Read_Callback(uint8_t* p_data, uint16_t size);

int main(void)
{
    uint8_t data[10] = {0};
    
    I2C_Configuration();
    
    while(1)
    {
        // Wait for I2C transaction to complete
    }
}

void I2C_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    I2C_InitTypeDef I2C_InitStruct;
    NVIC_InitTypeDef NVIC_InitStruct;
    
    // Enable I2C and GPIO clocks
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
    
    // Configure GPIO pins for I2C
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_I2C1);
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOB, &GPIO_InitStruct);
    
    // Configure I2C
    I2C_InitStruct.I2C_Mode = I2C_Mode_SMBusSlave;
    I2C_InitStruct.I2C_OwnAddress1 = I2C_SLAVE_ADDRESS << 1;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_ClockSpeed = 100000; // 100 kHz
    I2C_Init(I2C1, &I2C_InitStruct);
    
    // Enable interrupts for I2C event and buffer interrupts
    NVIC_InitStruct.NVIC_IRQChannel = I2C1_EV_IRQn;
    NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStruct);
    NVIC_InitStruct.NVIC_IRQChannel = I2C1_ER_IRQn;
    NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStruct);
    
    // Enable I2C interrupts
    I2C_ITConfig(I2C1, I2C_IT_EVT | I2C_IT_BUF, ENABLE);
    
    // Enable I2C
    I2C_Cmd(I2C1, ENABLE);
}

void I2C_Read_Callback(uint8_t* p_data, uint16_t size)
{
    // Handle I2C read request here
}

void I2C1_EV_IRQHandler(void)
{
    uint8_t data[10] = {0};
    uint16_t data_len = 0;
    
    if(I2C_GetITStatus(I2C1, I2C_IT_ADDR))
    {
        // Address matched, read request
        if(I2C_GetTransferDirection(I2C1) == I2C_DirectionReceiver)
        {
            // Call callback function to handle read request
            I2C_Read_Callback(data, data_len);
        }
    }
    else if(I2C_GetITStatus(I2C1, I2C_IT_RXNE))
    {
        // Data received
    }
    else if(I2C_GetITStatus(I2C1, I2C_IT_TXE))
    {
        // Data transmitted
    }
    else if(I2C_GetITStatus(I2C1, I2C_IT_STOPF))
    {
        // Stop condition detected
        I2C_ClearITPendingBit(I2C1, I2C_IT_STOPF);
    }
}

void I2C1_ER_IRQHandler(void)
{
    // Handle I2C errors here
}

该程序首先配置了GPIO和I2C模块，然后在主循环中等待I2C事务完成。当I2C事件发生时，`I2C1_EV_IRQHandler()`中断处理程序将被调用。在该函数中，程序检查I2C事件类型，并针对不同的事件类型执行不同的操作。例如，如果地址匹配，则表示收到了读取请求，因此程序将调用回调函数来处理该请求。如果数据接收或数据传输，则程序将读取或写入收到的数据。如果检测到停止条件，则程序将清除中断标志位。最后，如果出现I2C错误，则将在`I2C1_ER_IRQHandler()`中断处理程序中处理。