X-CUBE-SPN7, speed calculation，counter_ARR_Bemf = __HAL_TIM_GetCounter(&LF_TIMx); The variable counter_ARR_Bemf is step_time ? why El_Speed_Hz = (int32_t)((SIXSTEP_parameters.SYSCLK_frequency)/(prsc))/(__HAL_TIM_GetAutoreload(&LF_TIMx)*6);

[zquan.1]

I can speak English ​ a little, sorry!

[Cristiana SCARAMEL]

Hi @zquan.1​ and welcome to the ST Community.

The variable counter_ARR_Bemf store the last value of Autoreload for Low Frequency timer

With El_Speed_Hz = (int32_t)((SIXSTEP_parameters.SYSCLK_frequency)/(prsc))/(__HAL_TIM_GetAutoreload(&LF_TIMx)*6);

you get the *Eletrical* Motor Speed from ARR value of Commutation / LF TIM

I hope these info can help you; if so, consider to mark it as best answer by clicking the label "Select as Best".

[Cristiana SCARAMEL]

Hi @zquan.1​,

my reply solved your doubts?