2.2 硬件支持

MT6825编码器电路

驱动板电路

2.3 Cubemax配置及使用

2.4 项目代码实现

SPI外设初始化：

/* SPI1 init function */
void MX_SPI1_Init(void)
{

  /* USER CODE BEGIN SPI1_Init 0 */

  /* USER CODE END SPI1_Init 0 */

  /* USER CODE BEGIN SPI1_Init 1 */

  /* USER CODE END SPI1_Init 1 */
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_16BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_HIGH;
  hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_64;  //8 10.5Mbit/s 64 1.3125Mbits 16 5.25Mbit/s
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 10;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN SPI1_Init 2 */

  /* USER CODE END SPI1_Init 2 */

}

结构体及初始化：

typedef struct{
	uint16_t  cmd[3];
	uint16_t  rec_data[3];
	uint8_t  no_mag_warning_flag;
	uint8_t  over_speed_flag;
	uint8_t  pc1_flag;
	uint8_t  pc2_flag;
	uint8_t  pc1_count;
	uint8_t  pc2_count;
	uint8_t  err;
	uint32_t sample_data;
	uint32_t angle_data;
	uint32_t pre_angle_data;
}mag_enc_t;

extern mag_enc_t mag_enc;

/**********************************************************/
mag_enc_t mag_enc = {
    .cmd = {0x8300, 0x8400, 0x8500},
    .rec_data = {0, 0, 0},
    .no_mag_warning_flag = 0,
    .over_speed_flag = 0,
    .pc1_flag = 0,
    .pc2_flag = 0,
    .pc1_count = 0,
    .pc2_count = 0,
	.err = 0,
    .sample_data = 0,
	.angle_data =0,
	.pre_angle_data =0
};

SPI读取绝对值位置：

uint32_t SPI1_MT6825_fast_ReadData(void)
{
	short timeOut=1000;
	
	SPI1_CS_LOW;
//	HAL_SPI_Transmit(&hspi1 ,(unsigned char *)&mag_enc.cmd[0] ,1,200);
//	HAL_SPI_Receive(&hspi1 ,(unsigned char *)&mag_enc.rec_data[0] ,3,200);
    HAL_SPI_TransmitReceive(&hspi1 ,(unsigned char *)&mag_enc.cmd[0] ,(unsigned char *)&mag_enc.rec_data[0] ,3,200 );
	while( hspi1.State == HAL_SPI_STATE_BUSY )
	{
	  if (timeOut-- ==0) return 0;
	}   // wait for transmission complete
  SPI1_CS_HIGH;

  mag_enc.angle_data=((mag_enc.rec_data[0]&0x00FF)<<10)+((mag_enc.rec_data[1]&0xFC00)>>6)+((mag_enc.rec_data[1]&0x00F0)>>4);
  return mag_enc.angle_data;
}