Posted on September 13, 2016 at 10:49
Hello there,
I am trying to figure out how to interface with the Hall sensor module in STM32F4. I am not sure what does the commutation parameter (using mxCube) stand for really. Looking in the init code:
/**
* @brief Initializes the TIM Hall Sensor Interface and create the associated handle.
* @param htim: pointer to a TIM_HandleTypeDef structure that contains
* the configuration information for TIM module.
* @param sConfig: TIM Hall Sensor configuration structure
* @retval HAL status
*/
HAL_StatusTypeDef HAL_TIMEx_HallSensor_Init(TIM_HandleTypeDef *htim, TIM_HallSensor_InitTypeDef* sConfig)
{
TIM_OC_InitTypeDef OC_Config;
/* Check the TIM handle allocation */
if(htim == NULL)
{
return HAL_ERROR;
}
assert_param(IS_TIM_XOR_INSTANCE(htim->Instance));
assert_param(IS_TIM_COUNTER_MODE(htim->Init.CounterMode));
assert_param(IS_TIM_CLOCKDIVISION_DIV(htim->Init.ClockDivision));
assert_param(IS_TIM_IC_POLARITY(sConfig->IC1Polarity));
assert_param(IS_TIM_IC_PRESCALER(sConfig->IC1Prescaler));
assert_param(IS_TIM_IC_FILTER(sConfig->IC1Filter));
/* Set the TIM state */
htim->State= HAL_TIM_STATE_BUSY;
/* Init the low level hardware : GPIO, CLOCK, NVIC and DMA */
HAL_TIMEx_HallSensor_MspInit(htim);
/* Configure the Time base in the Encoder Mode */
TIM_Base_SetConfig(htim->Instance, &htim->Init);
/* Configure the Channel 1 as Input Channel to interface with the three Outputs of the Hall sensor */
TIM_TI1_SetConfig(htim->Instance, sConfig->IC1Polarity, TIM_ICSELECTION_TRC, sConfig->IC1Filter);
/* Reset the IC1PSC Bits */
htim->Instance->CCMR1 &= ~TIM_CCMR1_IC1PSC;
/* Set the IC1PSC value */
htim->Instance->CCMR1 |= sConfig->IC1Prescaler;
/* Enable the Hall sensor interface (XOR function of the three inputs) */
htim->Instance->CR2 |= TIM_CR2_TI1S;
/* Select the TIM_TS_TI1F_ED signal as Input trigger for the TIM */
htim->Instance->SMCR &= ~TIM_SMCR_TS;
htim->Instance->SMCR |= TIM_TS_TI1F_ED;
/* Use the TIM_TS_TI1F_ED signal to reset the TIM counter each edge detection */
htim->Instance->SMCR &= ~TIM_SMCR_SMS;
htim->Instance->SMCR |= TIM_SLAVEMODE_RESET;
/* Program channel 2 in PWM 2 mode with the desired Commutation_Delay*/
OC_Config.OCFastMode = TIM_OCFAST_DISABLE;
OC_Config.OCIdleState = TIM_OCIDLESTATE_RESET;
OC_Config.OCMode = TIM_OCMODE_PWM2;
OC_Config.OCNIdleState = TIM_OCNIDLESTATE_RESET;
OC_Config.OCNPolarity = TIM_OCNPOLARITY_HIGH;
OC_Config.OCPolarity = TIM_OCPOLARITY_HIGH;
OC_Config.Pulse = sConfig->Commutation_Delay;
TIM_OC2_SetConfig(htim->Instance, &OC_Config);
/* Select OC2REF as trigger output on TRGO: write the MMS bits in the TIMx_CR2
register to 101 */
htim->Instance->CR2 &= ~TIM_CR2_MMS;
htim->Instance->CR2 |= TIM_TRGO_OC2REF;
/* Initialize the TIM state*/
htim->State= HAL_TIM_STATE_READY;
return HAL_OK;
}
It seems that the timer is slaved through TRGO, but I cant quite understand this. I tried to increase commutation delay and rotate my BLDC motor shaft with hand in order to see either Input capture compare 1 interrupt will be delayed by the commutation time, but it was not. Am I understanding correctly that this is the destination of this parameter?
Also it is a bit confusing for me that commutation name is at any point connected with the hall sensor configuration, as this term is more likely used for motor current commutation.
I would really appreciate all help regarding this.
