Is it possible to change the rotation direction of the motor in sensorless mode in some way?

Is this a DC motor driven through an H-bridge? If so to change direction swap the sink and source at the bridge. DC motor direction is controlled by the polarity of the DC power to the motor. Typically an STM32 uses TIM1 to drive the two sides of the H-bridge, using PWM to vary speed and timer compare output polarity to set direction. TIM1 has the additional logic for deadtime when switching direction on the bridge, otherwise you can get a "shoot through" where sink and source are on at the same time on one leg of the bridge.

Jack Peacock

Dear Jack Peacock,

Thank you very much for your nswer. Yes I have DC motor driven through an H-bridge. My TIM1 looks the following:

static void MX_TIM1_Init(void)

{

 /* USER CODE BEGIN TIM1_Init 0 */

 /* USER CODE END TIM1_Init 0 */

 TIM_SlaveConfigTypeDef sSlaveConfig = {0};

 TIM_MasterConfigTypeDef sMasterConfig = {0};

 TIMEx_BreakInputConfigTypeDef sBreakInputConfig = {0};

 TIM_OC_InitTypeDef sConfigOC = {0};

 TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};

 /* USER CODE BEGIN TIM1_Init 1 */

 /* USER CODE END TIM1_Init 1 */

 htim1.Instance = TIM1;

 htim1.Init.Prescaler = ((TIM_CLOCK_DIVIDER) - 1);

 htim1.Init.CounterMode = TIM_COUNTERMODE_CENTERALIGNED1;

 htim1.Init.Period = ((PWM_PERIOD_CYCLES) / 2);

 htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;

 htim1.Init.RepetitionCounter = (REP_COUNTER);

 htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;

 if (HAL_TIM_Base_Init(&htim1) != HAL_OK)

 {

  Error_Handler();

 }

 if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)

 {

  Error_Handler();

 }

 sSlaveConfig.SlaveMode = TIM_SLAVEMODE_TRIGGER;

 sSlaveConfig.InputTrigger = TIM_TS_ITR1;

 if (HAL_TIM_SlaveConfigSynchro(&htim1, &sSlaveConfig) != HAL_OK)

 {

  Error_Handler();

 }

 sMasterConfig.MasterOutputTrigger = TIM_TRGO_OC4REF;

 sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;

 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

 if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)

 {

  Error_Handler();

 }

 sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP1;

 sBreakInputConfig.Enable = TIM_BREAKINPUTSOURCE_ENABLE;

 sBreakInputConfig.Polarity = TIM_BREAKINPUTSOURCE_POLARITY_HIGH;

 if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)

 {

  Error_Handler();

 }

 sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP2;

 if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)

 {

  Error_Handler();

 }

 sBreakInputConfig.Source = TIM_BREAKINPUTSOURCE_COMP4;

 if (HAL_TIMEx_ConfigBreakInput(&htim1, TIM_BREAKINPUT_BRK2, &sBreakInputConfig) != HAL_OK)

 {

  Error_Handler();

 }

 sConfigOC.OCMode = TIM_OCMODE_PWM1;

 sConfigOC.Pulse = 0;

 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;

 sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;

 sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;

 sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;

 sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;

 if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)

 {

  Error_Handler();

 }

 sConfigOC.Pulse = 0;

 if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)

 {

  Error_Handler();

 }

 sConfigOC.Pulse = 0;

 if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)

 {

  Error_Handler();

 }

 sConfigOC.OCMode = TIM_OCMODE_PWM2;

 sConfigOC.Pulse = 0;

 sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;

 if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_4) != HAL_OK)

 {

  Error_Handler();

 }

 sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_ENABLE;

 sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_ENABLE;

 sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_1;

 sBreakDeadTimeConfig.DeadTime = ((DEAD_TIME_COUNTS) / 2);

 sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;

 sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;

 sBreakDeadTimeConfig.BreakFilter = 0;

 sBreakDeadTimeConfig.BreakAFMode = TIM_BREAK_AFMODE_INPUT;

 sBreakDeadTimeConfig.Break2State = TIM_BREAK2_ENABLE;

 sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;

 sBreakDeadTimeConfig.Break2Filter = 3;

 sBreakDeadTimeConfig.Break2AFMode = TIM_BREAK_AFMODE_INPUT;

 sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;

 if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)

 {

  Error_Handler();

 }

 /* USER CODE BEGIN TIM1_Init 2 */

 /* USER CODE END TIM1_Init 2 */

 HAL_TIM_MspPostInit(&htim1);

}

So how should I change the polarity setup to change the rotation direction in every 3 ms?

I am very new in motor control, you would help me a lot !!

Thank you

I have this kind of motor:

https://www.maxongroup.com/maxon/view/content/ECX-Detailsite

With different controller it was possible to do it, probably I said the motor type badly.