Input capture goes to infinite loop

[arunl4g]

Posted on June 09, 2015 at 13:29

hej all,

my program works when i measure but the problem is its goes to the infite loop. i would like to measure and return the value . but i cant write program in that way . if i change the below program then it wont work . can anyone help me to get out of this. thank you ... i am using stm32f407 discovery board.

the below one is intialization.

/new one TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_TimeBaseStructure.TIM_Prescaler =168 - 1; TIM_TimeBaseStructure.TIM_Period = 65535; TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); GPIO_InitTypeDef GPIO_IniStructure; NVIC_InitTypeDef NVIC_IniStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE); GPIO_IniStructure.GPIO_Pin = GPIO_Pin_11; GPIO_IniStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_IniStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_IniStructure.GPIO_OType = GPIO_OType_PP; GPIO_IniStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOE, &GPIO_IniStructure); GPIO_PinAFConfig(GPIOE, GPIO_PinSource11, GPIO_AF_TIM1); //timer alternative function mapping NVIC_IniStructure.NVIC_IRQChannel = TIM1_CC_IRQn; //TIM1 Capture Compare Interrupt NVIC_IniStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_IniStructure.NVIC_IRQChannelSubPriority = 1; NVIC_IniStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_IniStructure); TIM_ICInitTypeDef TIM_ICInitStructure; TIM_ICInitStructure.TIM_Channel = TIM_Channel_2; TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_ICInitStructure.TIM_ICFilter = 0x0; TIM_ICInit(TIM1, &TIM_ICInitStructure); TIM_Cmd(TIM1, ENABLE); TIM_ITConfig(TIM1, TIM_IT_CC2, ENABLE); the below one has to give me proper value but i am not measuring the proper signal . void TIM1_CC_IRQHandler(void) { if(TIM_GetITStatus(TIM1, TIM_IT_CC2) == SET) { TIM_ClearITPendingBit(TIM1, TIM_IT_CC2); if(CaptureNumber == 0) { //sprintf(processcommand, ''%d'', IC3ReadValue2); //printf( ''IC3ReadValue2 %d \n'', IC3ReadValue1 ); //usart_SEND (USART6,processcommand); IC3ReadValue1 = TIM_GetCapture2(TIM1); CaptureNumber = 1; } else if(CaptureNumber == 1) { IC3ReadValue2 = TIM_GetCapture2(TIM1); //printf( ''IC3ReadValue2 %d \n'', IC3ReadValue2 ); if (IC3ReadValue2 > IC3ReadValue1) { Capture = 0; Capture = (IC3ReadValue2 - IC3ReadValue1); } else if (IC3ReadValue2 < IC3ReadValue1) { Capture = 0; Capture = ((0xFFFF - IC3ReadValue1) + IC3ReadValue2); } else { Capture = 0; } TIM1Freq = (uint32_t) SystemCoreClock / Capture; sprintf(processcommand, ''%d'', TIM1Freq); usart_SEND (USART6,processcommand); usart_SEND (USART6,''\n\r''); //TIM1Freq = (uint32_t) SystemCoreClock / Capture1; CaptureNumber = 0; } } } the below diagram shows where it goes in to while loop

[Tesla DeLorean]

Posted on June 09, 2015 at 14:30

Probably because it fires more frequently than the USART or your debugging can separate.

volatile uint32_t TIM1Freq;
uint16_t Capture, ReadValue1, Readvalue2;
void TIM1_CC_IRQHandler(void)
{
static int CaptureNumber = 0;
if (TIM_GetITStatus(TIM1, TIM_IT_CC2) == SET)
{
TIM_ClearITPendingBit(TIM1, TIM_IT_CC2);
if (CaptureNumber == 0)
{
ReadValue1 = TIM_GetCapture2(TIM1);
CaptureNumber = 1;
}
else if(CaptureNumber == 1)
{
ReadValue2 = TIM_GetCapture2(TIM1);
Capture = (ReadValue2 - ReadValue1); // Understand unsigned 16-bit math
if (Capture) // Catch division by zero
TIM1Freq = SystemCoreClock / (uint32_t)Capture;
else
TIM1Freq = 0;
// DON'T print here, read TIM1Freq in main() loop
CaptureNumber = 0;
}
else
CaptureNumber = 0;
}
}
while(1)
{
TIM1Freq = 0;
while(TIM1Freq == 0);
printf(''%d
'', TIM1Freq);
}

[arunl4g]

Posted on June 11, 2015 at 13:28

Thank you clive.