Posted on November 25, 2014 at 13:08Hi,
i want to capture time signal on PA0. I use a FreeRtos. My code:
//Input capture mode
TIM1->CR1 = 0x0;
TIM2->CCMR1=0x0;
TIM2->CCER =0x0;
TIM2->CR1 |=TIM_CR1_CMS ;
TIM2->CR1 |=TIM_CR1_DIR;
TIM2->CCMR1 |=TIM_CCMR1_CC1S_0 ;// CC1 channel is configured as input, IC1 is mapped on TI1
TIM2->CCMR1 |=TIM_CCMR1_IC1F_0 |TIM_CCMR1_IC1F_1 ;//f SAMPLING N=8
//TIM2->CCER |=TIM_CCER_CC1P ;//OC1 active high
//TIM2->CCMR1&=~TIM_CCMR1_IC1PSC ;//Prescaler
TIM2->CCER|=TIM_CCER_CC1E; // Capture enabled
//TIM2->CR1|=TIM_CR1_ARPE ; autoreload
TIM2->CR1|=TIM_CR1_CEN; // TIM2 enable
TIM2->DIER|=TIM_DIER_CC1IE;// interrupt enable
TIM2->PSC = 23999;
NVIC_EnableIRQ(TIM2_IRQn);
AND
void TIM2_IRQHandler(void)
{
if(TIM2->SR & TIM_SR_CC1IF)
{
TIM2->SR = ~TIM_SR_CC1IF;
TIM2->CNT = 0; //Zeruję licznik.
ECHO=TIM2->CCR1;
}
}
My signal on PA0 is PWM : 200ms high and 500ms low.
ECHO=TIM2->CCR1 is alway 700. Why?
Thanks.
