STM32F103 IIC代码

以下是一个示例STM32F103的I2C代码，用于从一个I2C设备读取数据：

#include "stm32f10x.h"

#define I2C_SPEED 100000 // I2C速度为100kHz
#define I2C_SLAVE_ADDRESS 0xA0 // I2C从设备地址

void I2C_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  I2C_InitTypeDef I2C_InitStructure;

  // 使能I2C时钟
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
  // 使能GPIO时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  // 配置GPIO为开漏输出
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // 配置I2C
  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 = I2C_SPEED;
  I2C_Init(I2C1, &I2C_InitStructure);

  // 使能I2C
  I2C_Cmd(I2C1, ENABLE);
}

void I2C_ReadData(uint8_t *buffer, uint8_t length)
{
  uint8_t i;

  // 发送启动信号
  I2C_GenerateSTART(I2C1, ENABLE);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

  // 发送从设备地址
  I2C_Send7bitAddress(I2C1, I2C_SLAVE_ADDRESS, I2C_Direction_Receiver);
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

  // 读取数据
  for(i = 0; i < length; i++)
  {
    if(i == length - 1)
    {
      // 最后一个字节不应答
      I2C_AcknowledgeConfig(I2C1, DISABLE);
      I2C_GenerateSTOP(I2C1, ENABLE);
    }

    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
    buffer[i] = I2C_ReceiveData(I2C1);
  }

  // 恢复应答位
  I2C_AcknowledgeConfig(I2C1, ENABLE);
}

int main(void)
{
  uint8_t buffer[10];

  I2C_Configuration();

  // 从设备读取数据
  I2C_ReadData(buffer, 10);

  while(1);
}