两个stm32单片机之间的iic通信例程，从机发送主机接收

以下是一个示例代码，用于两个STM32单片之间的IIC通信。在该例程中，一个STM32作为从设备（Slave）发送数据给另一个STM32作为主设备（Master）进行接收。

从设备发送数据给主设备：

#include "stm32f4xx.h"
#include "stm32f4xx_i2c.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"

#define I2C_ADDRESS 0x08 // 主设备地址

I2C_InitTypeDef I2C_InitStruct;
GPIO_InitTypeDef GPIO_InitStruct;

void I2C_Configuration(void)
{
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    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);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_I2C1);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);

    I2C_DeInit(I2C1);
    I2C_InitStruct.I2C_ClockSpeed = 100000;
    I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_OwnAddress1 = 0x07; // 从设备地址
    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_Init(I2C1, &I2C_InitStruct);

    I2C_Cmd(I2C1, ENABLE);
}

void I2C_SendData(uint8_t* data, uint8_t dataLength)
{
    while (I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, I2C_ADDRESS, I2C_Direction_Transmitter);
    while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    for (uint8_t i = 0; i < dataLength; i++)
    {
        I2C_SendData(I2C1, data[i]);
        while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    }

    I2C_GenerateSTOP(I2C1, ENABLE);
}

int main(void)
{
    uint8_t data[] = "Hello";

    I2C_Configuration();

    while (1)
    {
        I2C_SendData(data, sizeof(data));
        delay(500);
    }
}

主设备接收从设备发送的数据：

#include "stm32f4xx.h"
#include "stm32f4xx_i2c.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_usart.h"

#define I2C_ADDRESS 0x07 // 从设备地址

I2C_InitTypeDef I2C_InitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
USART_InitTypeDef USART_InitStruct;

void I2C_Configuration(void)
{
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    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);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_I2C1);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);

    I2C_DeInit(I2C1);
    I2C_InitStruct.I2C_ClockSpeed = 100000;
    I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_OwnAddress1 = 0x08; // 主设备地址
    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_Init(I2C1, &I2C_InitStruct);

    I2C_Cmd(I2C1, ENABLE);
}

void USART_Configuration(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_USART1);

    USART_DeInit(USART1);
    USART_InitStruct.USART_BaudRate = 9600;
    USART_InitStruct.USART_WordLength = USART_WordLength_8b;
    USART_InitStruct.USART_StopBits = USART_StopBits_1;
    USART_InitStruct.USART_Parity = USART_Parity_No;
    USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStruct);

    USART_Cmd(USART1, ENABLE);
}

void I2C_ReceiveData(void)
{
    uint8_t receivedData[10];
    uint8_t dataLength = 0;

    while (I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_AcknowledgeConfig(I2C1, ENABLE);
    I2C_GenerateSTART(I2C1, ENABLE);
    while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, I2C_ADDRESS, I2C_Direction_Receiver);
    while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

    while (dataLength < sizeof(receivedData))
    {
        if (I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED))
        {
            receivedData[dataLength++] = I2C_ReceiveData(I2C1);
        }
    }

    I2C_AcknowledgeConfig(I2C1, DISABLE);
    I2C_GenerateSTOP(I2C1, ENABLE);

    for (uint8_t i = 0; i < dataLength; i++)
    {
        while (!USART_GetFlagStatus(USART1, USART_FLAG_TXE));
        USART_SendData(USART1, receivedData[i]);
    }
}

int main(void)
{
    I2C_Configuration();
    USART_Configuration();

    while (1)
    {
        I2C_ReceiveData();
        delay(500);
    }
}

在从设备中，我们使用`I2C_SendData()`函数发送数据给主设备。首先，我们等待IIC总线空闲，然后生成START信号，接着发送主设备地址和写入位，然后通过循环发送数据字节。最后，我们生成STOP信号结束传输。

在主设备中，我们使用`I2C_ReceiveData()`函数接收从设备发送的数据。首先，我们等待IIC总线空闲，然后生成START信号，接着发送从设备地址和读取位。然后，我们循环接收数据字节，并通过USART发送到串口进行打印。

请注意：以上示例代码是基于STM32F4系列的，使用了STM32标准外设库（Standard Peripherals Library）。如果你使用其他型号的STM32单片机或者使用了不同的开发库，可能需要进行相应的调整。

希望这个例程对你有所帮助！如果还有其他问题，请随时提问。