Timer XOR ON / Hall Sensor Mode Edge Trigger Problem

[rowellsa]

Using a NUCLEO-G491RE and X-NUCLEO-IHM07M1 motor driver, I am trying to implement a Six-Step Commutation BLDC algorithm in a way that i can understand it myself. While researching , i found out that the TIM2 pins can be used simultaneously as Hall sensor triggers. In a way to understand how the interrupt will work, i implemented a very simple counter where the rising edge trigger of a 1kHz pwm signal is checked for trigger. However, i observed that, the polarity selection does not matter and the callback function triggers on both rising and falling edges of a signal. I am sure of this as i also tried with connecting a hall sensor to the pins. In addition, while keeping the other settings the same, i tried the same thing with a configuration where only Channel 1 is selected as Direct Input Compare and observed an expected result. Below are the codes:

Callback Function:

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) {



if (htim->Instance == TIM2) {





hall_reset_count++;



hallState = __HAL_TIM_GET_COUNTER(htim);

}

}

Only Input Capture :

static void MX_TIM2_Init(void)

{



/* USER CODE BEGIN TIM2_Init 0 */



/* USER CODE END TIM2_Init 0 */



TIM_ClockConfigTypeDef sClockSourceConfig = {0};

TIM_MasterConfigTypeDef sMasterConfig = {0};

TIM_IC_InitTypeDef sConfigIC = {0};



/* USER CODE BEGIN TIM2_Init 1 */



/* USER CODE END TIM2_Init 1 */

htim2.Instance = TIM2;

htim2.Init.Prescaler = 0;

htim2.Init.CounterMode = TIM_COUNTERMODE_UP;

htim2.Init.Period = 65535;

htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;

if (HAL_TIM_Base_Init(&htim2) != HAL_OK)

{

Error_Handler();

}

sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;

if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)

{

Error_Handler();

}

if (HAL_TIM_IC_Init(&htim2) != HAL_OK)

{

Error_Handler();

}

sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)

{

Error_Handler();

}

sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;

sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;

sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;

sConfigIC.ICFilter = 0;

if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)

{

Error_Handler();

}

/* USER CODE BEGIN TIM2_Init 2 */



/* USER CODE END TIM2_Init 2 */



}

Hall Sensor Mode:

static void MX_TIM2_Init(void)

{



/* USER CODE BEGIN TIM2_Init 0 */



/* USER CODE END TIM2_Init 0 */



TIM_ClockConfigTypeDef sClockSourceConfig = {0};

TIM_HallSensor_InitTypeDef sConfig = {0};

TIM_MasterConfigTypeDef sMasterConfig = {0};



/* USER CODE BEGIN TIM2_Init 1 */



/* USER CODE END TIM2_Init 1 */

htim2.Instance = TIM2;

htim2.Init.Prescaler = 0;

htim2.Init.CounterMode = TIM_COUNTERMODE_UP;

htim2.Init.Period = 65535;

htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;

if (HAL_TIM_Base_Init(&htim2) != HAL_OK)

{

Error_Handler();

}

sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;

if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)

{

Error_Handler();

}

sConfig.IC1Polarity = TIM_ICPOLARITY_RISING;

sConfig.IC1Prescaler = TIM_ICPSC_DIV1;

sConfig.IC1Filter = 12;

sConfig.Commutation_Delay = 0;

if (HAL_TIMEx_HallSensor_Init(&htim2, &sConfig) != HAL_OK)

{

Error_Handler();

}

sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC2REF;

sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)

{

Error_Handler();

}

/* USER CODE BEGIN TIM2_Init 2 */



/* USER CODE END TIM2_Init 2 */



}

[Sarra.S]

Hello @rowellsa, 

This behavior appears to be related to the TIM02 input capture polarity. These bits determine the edge sensitivity of the input capture:

• CC1P = 0 and CC1NP = 0: Sensitive to the rising edge.
• CC1P = 1 and CC1NP = 0: Sensitive to the falling edge.
• CC1P = 1 and CC1NP = 1: Sensitive to both rising and falling edges.

Could you read their values in the TIMx_CCER register