Posted on July 06, 2015 at 05:19Timer works in Input capture mode. It captures period of rectangular wave. I would like to get interrupt on each eighth front, but interrupt does not dependent of prescaler. Controller: stm32f030f6p6. There is code fragment indicatind problem.
&sharpdefine TIMER_TEMP TIM2
&sharpdefine TIMER_HUM TIM3
&sharpdefine GET_PERIOD_TEMP (TIM_GetCapture2(TIMER_TEMP))
&sharpdefine GET_PERIOD_HUM (TIM_GetCapture1(TIMER_HUM))
int temp = 0;
int hum = 0;
void PeriphInit(void)
{
GPIO_InitTypeDef gpio;
TIM_TimeBaseInitTypeDef tim;
TIM_ICInitTypeDef timIn;
NVIC_InitTypeDef nvic;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_StructInit(&gpio);
gpio.GPIO_Pin=GPIO_Pin_1;
gpio.GPIO_Mode=GPIO_Mode_AF;
gpio.GPIO_Speed=GPIO_Speed_50MHz;
gpio.GPIO_OType = GPIO_OType_PP;
gpio.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA,&gpio);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_2);
TIM_TimeBaseStructInit(&tim);
tim.TIM_Prescaler = (SystemCoreClock/12000000)-1;
tim.TIM_Period = 0xFFFFFFFF;
tim.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIMER_TEMP, &tim);
timIn.TIM_Channel = TIM_Channel_2;
timIn.TIM_ICPolarity = TIM_ICPolarity_Rising;
timIn.TIM_ICSelection = TIM_ICSelection_DirectTI;
timIn.TIM_ICPrescaler = TIM_ICPSC_DIV4;//This prescaler doesn't work
timIn.TIM_ICFilter = 0x0;
TIM_SelectInputTrigger(TIMER_TEMP, TIM_TS_TI2FP2);
TIM_SelectSlaveMode(TIMER_TEMP, TIM_SlaveMode_Reset);
TIM_PWMIConfig(TIMER_TEMP, &timIn);
TIM_SetCounter(TIMER_TEMP, 0);
nvic.NVIC_IRQChannel=TIM2_IRQn;
nvic.NVIC_IRQChannelPriority = 0;
nvic.NVIC_IRQChannelCmd = DISABLE;
NVIC_Init(&nvic);
NVIC_EnableIRQ(TIM2_IRQn);
TIM_ITConfig(TIMER_TEMP, TIM_IT_CC2, ENABLE);
TIM_Cmd(TIMER_TEMP, ENABLE);
}
void TIM2_IRQHandler()
{
temp = GET_PERIOD_TEMP;
TIM_ClearITPendingBit(TIMER_TEMP, TIM_FLAG_CC2);
}
int main()
{
PeriphInit();
while (1);
}
#timer
