在stm32l4r5中使用i2c

Question

我想将相机ov5640与stm32l4r5 nucleo-144套件一起使用。我们使用i2c来设置相机。我正在使用以下代码进行i2c通信。

#define OV5640_ADDR 0x78
int ov7670_init(I2C_HandleTypeDef *p_hi2c)
{
  sp_hi2c = p_hi2c;
  HAL_Delay(100);
  uint8_t reg;
  uint8_t buffer;
  reg = ov7670_read(OV5640_CHIPIDH, &buffer);
  if (buffer == 0x56)
  {
      reg = ov7670_read(OV5640_CHIPIDL, &buffer);
      if (buffer == 0x40)
      {
          return 0;
      }
      else
      {
          return 1;
      }
  }
  else
  {
      return 1;
  }
}

static int ov5640_write(uint16_t regAddr, uint8_t data)
{
  HAL_StatusTypeDef ret;
  do {
        ret = HAL_I2C_Mem_Write(sp_hi2c, OV5640_ADDR, regAddr, I2C_MEMADD_SIZE_8BIT, &data, 1, 100);
  } while (ret != HAL_OK && 0);
  return ret;
}


static int ov7670_read(uint16_t regAddr, uint8_t *data)
{
  HAL_StatusTypeDef ret;
  uint8_t regAddrMSB = regAddr >> 8;
  uint8_t regAddrLSB = regAddr & 0x00FF;
  do {
    ret = HAL_I2C_Master_Transmit(sp_hi2c, OV5640_ADDR, &regAddrMSB, 1, 100);
    ret |= HAL_I2C_Master_Transmit(sp_hi2c, OV5640_ADDR, &regAddrLSB, 1, 100);
    ret |= HAL_I2C_Master_Receive(sp_hi2c, OV5640_ADDR, data, 1, 100);
  } while (ret != HAL_OK && 0);
  return ret;
}

我使用STM32CUBEMX软件来设置i2c引脚，并生成用于初始化i2c引脚的相关代码。相机有i2c个寄存器，地址为16位。但是i2c通讯无法正常工作。我无法读取寄存器。