incrementation of a timer : problem

claire · ‎2012-05-14

Posted on May 14, 2012 at 17:40

hi,

i am working on the stm32discovery

i am trying to increment a timer (timer2 channel 1) each time the signal on the pin PA.05 is rising but the timer is random incrementing and not at each rising edge of the signal

i don't understand why ?

here is my code :

int main(void)

{

/* Configure Clocks for Application need */

RCC_Configuration();

/* Configure RTC Clocks */

//RTC_Configuration();

/* Configure SysTick IRQ and SysTick Timer to generate interrupts every 500Âµs */

RCC_GetClocksFreq(&RCC_Clocks);

//SysTick_Config(RCC_Clocks.HCLK_Frequency / 2000);

/* Enable GPIOs clock */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA,ENABLE);

/*PA.05 TIM2 channel 1*/

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;

GPIO_Init(GPIOA,&GPIO_InitStructure);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_TIM2);

TIM_InitStruct.TIM_Period = 849;

TIM_InitStruct.TIM_Prescaler = 0;

TIM_InitStruct.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM2,&TIM_InitStruct);

/*timer2 chanel 1 ETR pin PA5*/

TIM_ICInitStruct.TIM_Channel = TIM_Channel_1;

TIM_ICInitStruct.TIM_ICPolarity = TIM_ICPolarity_Rising;

TIM_ICInitStruct.TIM_ICSelection = TIM_ICSelection_DirectTI;

TIM_ICInitStruct.TIM_ICPrescaler = TIM_ICPSC_DIV1;

TIM_ICInitStruct.TIM_ICFilter = 0x0;

TIM_ICInit(TIM2, &TIM_ICInitStruct);

/*enable the TIM counter*/

TIM_Cmd(TIM2, ENABLE);

TIM_TIxExternalClockConfig(TIM2, TIM_TIxExternalCLK1Source_TI1, TIM_ICPolarity_Rising, 0);

TIM_ETRClockMode1Config(TIM2,TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted,0);

while (1){

SysTick_Config(RCC_Clocks.HCLK_Frequency / 2000);

bitStatut = GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_5);

increment = TIM_GetCapture1(TIM2);

Delay(100);

}

could you help me ?

thanks

Tesla DeLorean · ‎2013-02-25

Posted on February 25, 2013 at 18:21

Bonding PC6 to PA0 button input

void TIM3_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE); // AFIO required for remapping
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; // PC6 TIM3_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI1, TIM_ICPolarity_Rising, 0);
TIM_Cmd(TIM3, ENABLE);
}

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carl239955_st · ‎2013-02-25

Posted on February 25, 2013 at 20:16

Big THANK YOU! It was the RCC_APB2Periph_AFIO that solved my issue! You saved me alot of time.