Posted on September 08, 2011 at 18:12Hello,
sorry, I do not know how it's configured in the Keil source example. Anyhow, there's a similar module in the STM32 PMSM FOC SDK v3.0 to handle Hall sensor signals, here below an excerpt of the timer peripheral configuration:
...
/* Set full 16-bit working range */
TIM_HALLTimeBaseInitStructure.TIM_Period = U16_MAX;
TIM_HALLTimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInit(TIMx,&TIM_HALLTimeBaseInitStructure);
TIM_ICStructInit(&TIM_HALLICInitStructure);
TIM_HALLICInitStructure.TIM_Channel = TIM_Channel_1;
TIM_HALLICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;
TIM_HALLICInitStructure.TIM_ICFilter = pDParams_str->hInpCaptFilter;
TIM_ICInit(TIMx,&TIM_HALLICInitStructure);
/* Force input capture from TRC */
/* Disable the Channel 1: Reset the CC1E Bit */
TIMx->CCER &= CCER_CC1E_Reset;
TIMx->CCMR1 |= 0x03u; /* CCS1 = 0b11; */
TIMx->CCER |= CCER_CC1E_Set;
/* Force the TIMx prescaler with immediate access (no need of an update event)
*/
TIM_PrescalerConfig(TIMx, (u16) pDVars_str->hHALLMaxRatio,
TIM_PSCReloadMode_Immediate);
TIM_InternalClockConfig(TIMx);
/* Enables the XOR of channel 1, channel2 and channel3 */
TIM_SelectHallSensor(TIMx, ENABLE);
TIM_SelectInputTrigger(TIMx, TIM_TS_TI1F_ED);
TIM_SelectSlaveMode(TIMx,TIM_SlaveMode_Reset);
/* Source of Update event is only counter overflow/underflow */
TIM_UpdateRequestConfig(TIMx, TIM_UpdateSource_Regular);
...
With this setup, the counter is reset every time there's a rising or falling edge on each of the internally XORed H1,H2,H3 (TI1F_ED, which is the OR of TI1F_Rising and TI1F_Falling, is used as trigger input by the slave mode controller) and its last value is stored in the CCR1 (TRC is used to force a capture). Figure 77 - in the STM32 reference Manual (RM0008) - is explanatory.
About the prescaler, in the SDK's Hall sensor module, it's constantly adjusted in order to always have the best resolution. I invite you to have a look at the User Manual UM1052, figures 44, 45 and 46.
Best regards,
Dino
Any help?
so, my motor speed is 5000rpm what is the best config of PSC for timer not overflow?
// define timer clock
// between two changes on the hall sensor lines on the lowest rotation
// speed (eg. 1/100 from max. speed) the timer must not overflow
// define timer counter clock appropriate
// timer base configuration
// 126 => 3,5s till overflow ; 285,714kHz TimerClock [36MHz/Prescaler]
TIM_TimeBaseStructure.
TIM_Prescaler
=
126
; TIM_TimeBaseStructure.
TIM_CounterMode
= TIM_CounterMode_Up; TIM_TimeBaseStructure.
TIM_Period
=
65535
; TIM_TimeBaseStructure.
TIM_ClockDivision
=
0
; TIM_TimeBaseStructure.
TIM_RepetitionCounter
=
0
; TIM_TimeBaseInit
(
TIM4, &TIM_TimeBaseStructure
)
; i not understand why 126
