HAL STM32 I2C方式读取MT6701磁编码器获取角度例程

---

• 📍相关篇《Arduino通过I2C驱动MT6701磁编码器并读取角度数据》
• 🎈《STM32 软件I2C方式读取MT6701磁编码器获取角度例程》
• 📌MT6701当前最新文档资料：https://www.magntek.com.cn/upload/MT6701_Rev.1.8_%E4%B8%AD%E6%96%87%E7%89%88.pdf
• 🔰MT6701芯片和AS5600从软件读取对比，只是读取的寄存器和访问的设备地址不同而已，所以稍作修改即可实现通用一个驱动模板。

📙MT6701 IIC接口电路

• 🔖 第八引脚,直接接到VCC，或者增加上拉电阻也可以。

⛳MT6701 I2C 读取角度操作

MT6701做为I2C从机的地址是b’0000110（这一地址可以通过编程改为b’1000110 ）。14位绝对角度数据（2的14次方，16384）保存在0x03和0x04寄存器中，请按照如图-20所示的读取0x03和0x04的角度数据。
注意：要先读0x03，再读0x04。

⛳注意事项

• ✨在MT6701芯片和径向磁铁一定要保持稳定的空间距离，一旦空间距离有较大的变化，在读取MT6701芯片寄存器数据就可能出现最大值情况。在检测时，芯片和径向磁铁轴向和径向都需要相对稳定。
  
• 🌟在选择通讯线材上，尽量选择好一点的线材，如果使用杜邦线连接，最好将连接线独立分开的单根进行连接，不要使用并排的杜邦线进行连接，对使用硬件I2C通讯有很大的影响。甚至读取不到，软件方式对这方面要求没有这么高。

📒EEPROM编程

• 🌿相关寄存器位：
  
• 📜编程步骤：
  

📓STM32CubeMX配置

• 🌿选择一个I2C接口：（快速模式：400KHz,普通模式：100KHz）
  

📙业务代码

• 🌿对I2C设备地址扫描实现：

	printf("Scanning I2C bus:\r\n");
	HAL_StatusTypeDef result;

 	for (uint8_t i=1; i<255; i++)
 	{
 	  /*
 	   * the HAL wants a left aligned i2c address
 	   * &hi2c1 is the handle
 	   * (uint16_t)(i<<1) is the i2c address left aligned
 	   * retries 2	重复次数
 	   * timeout 20    超时
		MT6701 i2c address:（0xC = 0x6 << 1）
 	   */
 	  result = HAL_I2C_IsDeviceReady(&hi2c1, (uint16_t)(i<<1), 2, 20);
 //	  result = HAL_I2C_Master_Transmit(&hi2c1,(uint16_t)i<<1,0,0,20); //同上
 	  if (result != HAL_OK) // HAL_ERROR or HAL_BUSY or HAL_TIMEOUT
 	  {
 		  printf("."); // No ACK received at that address
 	  }
 	  if (result == HAL_OK)
 	  {
 		  printf("0x%X", i); // Received an ACK at that address
 	  }
 	}
 	printf("\r\n");

• 可以扫描到3个地址，其中第一个0x6为MT6701真正的地址。

• 🌿读取角度数据实现：

/*	SlaveAddress：0x6<<1 
 * IIC 方式读取角度信息
 * 返回数据为 0 ~ 360 之间的浮点数
 */
float Read_Angle(void)
{
    uint32_t angle = 0;
    float fangle = 0.0f;
    uint8_t ReadBuffer1,ReadBuffer2;

    HAL_I2C_Mem_Read(&hi2c1,0xc,0x3,I2C_MEMADD_SIZE_8BIT,&ReadBuffer1,1,0XFF);
    angle = ReadBuffer1;
    angle <<= 8;
    HAL_I2C_Mem_Read(&hi2c1,0xc,0x4,I2C_MEMADD_SIZE_8BIT,&ReadBuffer2,1,0XFF);
    angle += ReadBuffer2;
    angle >>= 2;            //取数据高 14 位
    fangle = (float)(angle * 360.0f) / 16384.0f;

    return fangle;
}

• 🌿方向读取

#define DIR_RES    0X29        //数据高位寄存器地址
uint8_t Read_DIR(void)
{
	uint8_t  DIR=0;
	HAL_I2C_Mem_Read(&hi2c1,SlaveAddress,DIR_RES,I2C_MEMADD_SIZE_8BIT,&DIR,1,0XFF);
	 return (DIR&0x2);
}

• 🌿ABZ输出分辨率（脉冲圈）读取

#define Abz_ResH    0X30        //数据高位寄存器地址
#define Abz_ResL    0X31        //数据低位寄存器地址
uint16_t Read_ABZ(void)
{
    uint16_t AbzRes = 0;
    uint8_t ReadBuffer1,ReadBuffer2;

    HAL_I2C_Mem_Read(&hi2c1,SlaveAddress,Abz_ResH,I2C_MEMADD_SIZE_8BIT,&ReadBuffer1,1,0XFF);
    AbzRes = ReadBuffer1&0x3;
    AbzRes <<= 8;
    HAL_I2C_Mem_Read(&hi2c1,SlaveAddress,Abz_ResL,I2C_MEMADD_SIZE_8BIT,&ReadBuffer2,1,0XFF);
    AbzRes += ReadBuffer2;
    return AbzRes;
}

• 🌿通过 EEPROM编程，改变编码器方向。（默认是逆时针递增）

void programmEEPROM(void)
{
	uint8_t  DIR=0;
	uint8_t KEY1=0xB3;
	uint8_t KEY2=0x05;
	HAL_I2C_Mem_Read(&hi2c1,SlaveAddress,DIR_RES,I2C_MEMADD_SIZE_8BIT,&DIR,1,0XFF);
	DIR ^= 1<<1;  //方向翻转
	HAL_I2C_Mem_Write(&hi2c1,SlaveAddress,DIR_RES,I2C_MEMADD_SIZE_8BIT,&DIR,1,0XFF);
	HAL_I2C_Mem_Write(&hi2c1,SlaveAddress,0x09,I2C_MEMADD_SIZE_8BIT,&KEY1,1,0XFF);
	HAL_I2C_Mem_Write(&hi2c1,SlaveAddress,0x0A,I2C_MEMADD_SIZE_8BIT,&KEY2,1,0XFF);
	HAL_Delay(800);
	
	
}

• 📝测试代码

int main(void)
{

  /* USER CODE BEGIN 1 */
	int16_t angle;
	float angle_f;
	uint8_t  dir=0;
  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_I2C1_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
	printf("Scanning I2C bus:\r\n");
	HAL_StatusTypeDef result;

 	for (uint8_t i=1; i<255; i++)
 	{
 	  /*
 	   * the HAL wants a left aligned i2c address
 	   * &hi2c1 is the handle
 	   * (uint16_t)(i<<1) is the i2c address left aligned
 	   * retries 2	重复次数
 	   * timeout 20    超时
		MT6701 i2c address:（0xC = 0x6 << 1）
 	   */
// 	  result = HAL_I2C_IsDeviceReady(&hi2c1, (uint16_t)(i<<1), 2, 20);
 	  result = HAL_I2C_Master_Transmit(&hi2c1,(uint16_t)i<<1,0,0,20); //同上
		if (result != HAL_OK) // HAL_ERROR or HAL_BUSY or HAL_TIMEOUT
 	  {
 		  printf("."); // No ACK received at that address
 	  }
 	  if (result == HAL_OK)
 	  {
 		  printf("0x%X", i); // Received an ACK at that address
 	  }
 	}
 	printf("\r\n");
		
	  dir = Read_DIR() ;
	printf("DIR:%d",dir);
	HAL_Delay(200);	
#if defined(PROGRAM_ENABLE)
	printf("-------------------- MT6701 programm test --------------------\r\n");
	programmEEPROM();
#endif

	HAL_Delay(3000);
	dir = Read_DIR() ;
		printf("-------------------- MT6701 angle test --------------------\r\n");
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
//		i2c_mt6701_get_angle(&angle, &angle_f);
//		printf("angle = %d\t%.03f\r\n", angle, angle_f);
//		angle_f = Read_Angle();
//		printf("angle= %.1f\r\n",  angle_f);
		i2c_mt6701_get_angle(&angle, &angle_f);
		uint16_t AbzRes = Read_ABZ();		
		printf("Raw_Angle = %d\tAngle：%.1f,AbzRes:%d DIR:%d\r\n", angle, angle_f,AbzRes,dir);

		HAL_Delay(500);
		HAL_GPIO_TogglePin(LED1_GPIO_Port,LED1_Pin);
  }
  /* USER CODE END 3 */
}

📚测试工程

• 🌿硬件I2C方式

链接：https://pan.baidu.com/s/1l4gElhcqn6mg6cWYaHG4Wg?pwd=kuub 
提取码：kuub

• 🌿硬件I2C中断方式

链接：https://pan.baidu.com/s/1W2vZRmQPNe4VU6dKFc9xJQ?pwd=tzfl 
提取码：tzfl

• 🌿硬件I2C中断+DMA方式

链接：https://pan.baidu.com/s/138bIpgdeMii6GkKLJEPeMg?pwd=sl8a 
提取码：sl8a