input frequency capture

pandi — Fri, 19 Jan 2024 07:05:04 GMT

Hi everyone

how to configure input capture mode KV31F512VLL12 guide me and if you have sample program give to me help for us.

I `m trying this code correct or not if not means any changes guide me

void TIM1_init(void) {

SIM->SCGC5 |= SIM_SCGC5_PORTB(1);

PORTB->PCR[0] = PORT_PCR_MUX(0x3); // Set pin as ALT3 (TIM1_CH1)

SIM->SCGC6 |= SIM_SCGC6_FTM1(1);

FTM1->SC = 0;

FTM1->MOD = 1999;

FTM1->CONTROLS[1].CnSC = FTM_CnSC_MSB_MASK | FTM_CnSC_ELSB_MASK;

FTM1->CONTROLS[1].CnV = 1000;

FTM1->SC = FTM_SC_PS(7) | FTM_SC_TOF(1);

}

void TIM2_init(void) {

// Enable clock for PORTA

SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK;

PORTA->PCR[1] = PORT_PCR_MUX(0x3); // Set pin as ALT3 (TIM2_CH1)

SIM->SCGC6 |= SIM_SCGC6_FTM2(1);

FTM2->SC = 0;

FTM2->CONTROLS[1].CnSC = FTM_CnSC_ELSA_MASK | FTM_CnSC_ELSB_MASK |FTM_CnSC_CHIE_MASK;

FTM2->SC = FTM_SC_PS(7) | FTM_SC_TOF(1);

NVIC_EnableIRQ(FTM2_IRQn);

}

void FTM2_IRQHandler() {

// Clear channel flag

FTM2->CONTROLS[1].CnSC &= ~FTM_CnSC_CHF_MASK;

if (gap == 0) {

counter0 = FTM2->CONTROLS[1].CnV;

gap = 1;

} else {

counter1 = FTM2->CONTROLS[1].CnV;

if (counter1 > counter0) {

Counter = counter1 - counter0;

Frequency = 10000 / Counter;

} else {

Counter = counter1 + 0xFFFF - counter0 + 1;

Frequency = 10000 / Counter;

}

counter0 = counter1;

}

Thank you

PANDI

Re: input frequency capture

xiangjun_rong — Tue, 23 Jan 2024 07:53:16 GMT

Hi, Pandi,

When you input a tested signal to FTM2_CH1 pin, can you enter the FTM2_IRQHandler()?

If you can, it is okay, in the FTM2_IRQHandler(), you can check the overflow flag, if it is set, just clear the flag, and add 0xFFFF. While, you can assign the FTM2_MOD register to 0xFFFF in the FTM2 init code.

Void FTM2_ISR(void)
{

if(FTM2_STATUS&0x02)
{

FTM2_STATUS&=0xFD;
tempPrev=temp;
temp=FTM0_C0V; //read FTM0 counter register
diff=temp-tempPrev;

if(FTM2_SC&0x80)

{
diff=0xFFFF+diff;

FTM2_SC&=~(0x80); //clear overflow flag
GPIOC_PTOR=0x80;
asm("nop"); //set a break point here
}
}

Hope it can help you

XiangJun Rong

topic Re: input frequency capture in Kinetis Microcontrollers

input frequency capture

Re: input frequency capture