stm32单片机iic程序

下面是一个基于STM32的I2C程序示例，用于从I2C设备读取数据：

#include "stm32f10x.h"

#define I2C_SPEED         100000
#define I2C_SLAVE_ADDRESS 0xA0

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

  /* Enable GPIOB clocks */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  /* Configure PB6 and PB7 as I2C pins */
  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);

  /* Enable I2C1 clocks */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

  /* Configure I2C1 */
  I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
  I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
  I2C_InitStructure.I2C_OwnAddress1 = I2C_SLAVE_ADDRESS;
  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);

  /* Enable I2C1 */
  I2C_Cmd(I2C1, ENABLE);
}

uint8_t I2C_Read(uint8_t device_address, uint8_t register_address)
{
  uint8_t data;

  /* Send start condition */
  I2C_GenerateSTART(I2C1, ENABLE);

  /* Wait for start condition to be sent */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

  /* Send device address */
  I2C_Send7bitAddress(I2C1, device_address, I2C_Direction_Transmitter);

  /* Wait for address to be sent */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

  /* Send register address */
  I2C_SendData(I2C1, register_address);

  /* Wait for data to be sent */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

  /* Send repeated start condition */
  I2C_GenerateSTART(I2C1, ENABLE);

  /* Wait for start condition to be sent */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

  /* Send device address */
  I2C_Send7bitAddress(I2C1, device_address, I2C_Direction_Receiver);

  /* Wait for address to be sent */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

  /* Disable acknowledge */
  I2C_AcknowledgeConfig(I2C1, DISABLE);

  /* Send stop condition */
  I2C_GenerateSTOP(I2C1, ENABLE);

  /* Wait for data to be received */
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));

  /* Read data */
  data = I2C_ReceiveData(I2C1);

  /* Enable acknowledge */
  I2C_AcknowledgeConfig(I2C1, ENABLE);

  return data;
}

int main(void)
{
  uint8_t data;

  /* Initialize I2C */
  I2C_Configuration();

  /* Read data from I2C device */
  data = I2C_Read(I2C_SLAVE_ADDRESS, 0x00);

  while(1);
}

该程序使用了STM32的I2C库函数。其中，I2C_Read()函数用于读取I2C设备的数据。在该函数中，首先发送一个启动条件，然后发送I2C设备地址和要读取的寄存器地址，接着发送一个重复启动条件，然后发送I2C设备地址和接收方向，最后读取数据并发送停止条件。在主函数中，首先初始化I2C，然后调用I2C_Read()函数从I2C设备读取数据。