TIM1_CC_IRQHandler is not called

[mfcprog]

Posted on April 11, 2012 at 20:46

Hi,

I`m working with the STM32F103XC processor (lqfp144 package) and I want to use the input capture mode for the Timer1. At the moment I didn`t get any timer interrupt while the I/O PE13 has a lot of rising edges.

Maybe there`s something wrong with the PE13 pin which has as alternative function TIM1_CH3.

Here`s my init code.

RCC->APB2ENR |= (

1

<<

6

);

// enable peripheral clock for GPIOE

/* INT input PE13 -> mit timer1 verwenden */

GPIOE->CRH &= ~

0x00F00000

;

// reset port-pin

GPIOE->CRH |=

0x00400000

;

// set input mode floating

RCC->APB2ENR |= RCC_APB2Periph_TIM1;

/* Enable the TIM3 global Interrupt */

NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQChannel; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =

0

; NVIC_InitStructure.NVIC_IRQChannelSubPriority =

1

; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); TIM_TimeBaseStructure.TIM_Period =

0xFFFF

; TIM_TimeBaseStructure.TIM_Prescaler =

1

; TIM_TimeBaseStructure.TIM_ClockDivision =

0

; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_RepetitionCounter =

0

; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); TIM_ICInitStructure.TIM_Channel = TIM_Channel_3; TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_IndirectTI;

//PE13

TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;

// Div:1, every edge

TIM_ICInitStructure.TIM_ICFilter =

0x0

; TIM_ICInit(TIM1, &TIM_ICInitStructure); TIM_ClearITPendingBit(TIM1, TIM_IT_CC3); TIM_ITConfig(TIM1, TIM_IT_CC3, ENABLE);

/* TIM enable counter */

TIM_Cmd(TIM1, ENABLE);

/* TIMER interrupt routine: wird nie aufgerufen */

void

TIM1_CC_IRQHandler (

void

) {

if

(TIM1->SR & TIM_IT_CC3) {

/* capture timer */

TIM1->SR = (

unsigned

short

)~TIM_FLAG_CC3; } } best regards

Hans

[Tesla DeLorean]

Posted on April 11, 2012 at 21:25

TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;

I think you need to use DIRECT, to use PE13 you're going to need to REMAP TIM1 otherwise it expects PA10.

INDIRECT would be using TIM1_CH4 as the source.

RCC->APB2ENR |= RCC_APB2Periph_AFIO; GPIO_PinRemapConfig(GPIO_FullRemap_TIM1, ENABLE);

[mfcprog]

Posted on April 12, 2012 at 10:42

[mfcprog]

Posted on April 12, 2012 at 16:31

Hi,

the input capture timer is now working but I didn`t get any input capture values (IC3ReadValue1, IC3ReadValue2) to measure the frequency (TIM3Freq) between two interrupts. IC3ReadValue1 and IC3ReadValue2 are always 0x00.

I also took a look into the STM32 input capture example, but they use the same settings (only for the TIM_GetCapture2 instead of the TIM_GetCapture3.

volatile unsigned short IC3ReadValue1 = 0, IC3ReadValue2 = 0;

volatile unsigned short CaptureNumber = 0;

volatile unsigned int Capture = 0;

volatile unsigned int TIM3Freq = 0;

void TIM1_CC_IRQHandler (void)

{

   unsigned char state = 0x00;

   if (TIM1->SR & TIM_IT_CC3)

 {  /* capture timer */

//clear pending bit

  TIM1->SR &= (unsigned short)~TIM_FLAG_CC3;

if(CaptureNumber == 0)

     {

       /* Get the Input Capture value */

       IC3ReadValue1 = TIM3->CCR3; //TIM_GetCapture2(TIM3);

    if(IC3ReadValue1)

     IC3ReadValue1 = IC3ReadValue1;

       CaptureNumber = 1;

     }

  else if(CaptureNumber == 1)

     {

       /* Get the Input Capture value */

       IC3ReadValue2 = TIM3->CCR3; //TIM_GetCapture2(TIM3);

       if(IC3ReadValue2)

     IC3ReadValue2 = IC3ReadValue2;

       /* Capture computation */

       if (IC3ReadValue2 > IC3ReadValue1)

       {

         Capture = (IC3ReadValue2 - IC3ReadValue1);

       }

       else

       {

         Capture = ((0xFFFF - IC3ReadValue1) + IC3ReadValue2);

       }

       /* Frequency computation */

       TIM3Freq = (unsigned int) 36000000 / Capture;

       CaptureNumber = 0;

  }

}

best regards

Hans

[mfcprog]

Posted on April 13, 2012 at 10:47

I found my error: TIM3->CCR3 instead of TIM1->CCR3. Now I get some values in the CCRr3 register at the CCR3 interrupt, but I`m not sure how I have to calculate the frequency  from the input-capture-signal.

For example: the input-capture-signal has a frequency of 24Hz I get a frequency of 240Hz.

Here are my settings:

unsigend

short

prescaler = (

36000000

-

1000

) -

1

; TIM_TimeBaseStructure.TIM_Period =

0xFFFF

; TIM_TimeBaseStructure.TIM_Prescaler =

0

; TIM_TimeBaseStructure.TIM_ClockDivision =

0

; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_RepetitionCounter =

0

; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); TIM_PrescalerConfig(TIM1,prescaler, TIM_PSCReloadMode_Immediate); And this is my interrupt routine

volatile

unsigned

char

counter =

0x00

;

volatile

unsigned

short

capture =

0x00

;

volatile

unsigned

short

frequency =

0x00

;

void

TIM1_CC_IRQHandler(

void

) {

if

(TIM_GetITStatus(TIM1, TIM_IT_CC3) !=RESET) {

if

(!counter) {

/* Get the Input Capture value */

IC1Value = TIM1->CCR3; counter++; }

else

if

(counter) { counter =

0x00

; IC2Value = TIM1->CCR3;

if

(IC2Value > IC1Value) capture = IC2Value - IC1Value;

else

capture = (

0xFFFF

- IC1Value) + IC2Value;

// -> the capture value is always 0x4B

//frequency of the signal

frequency =

36000

/ (2 * capture); } TIM_ClearITPendingBit(TIM1, TIM_IT_CC3); } } As I found out if the APB prescaler is not 1 the timer clock frequency is set to twice the frequency of the APB domain which is 36MHz. -> therefore I divided the frequency-value by 2 (frequency =

36000

/ (2 * capture);).

best regards

Hans