STM32F030R8 Time base setup issue

[countach]

Posted on July 05, 2016 at 12:44

Hi Sir/Madam:

I've encounter a issue about setting Time base on STM32F030R8.I used TIM14 to be time base.When I check the 10ms time base in stm32f0xx_it.c.That was worked normally.But, I used it to set time flag in main.cIt's worked abnormal.The waveform isn't regular(not 10ms waveform).How do I solve it?Please help me.Thank you.Code is as below:Main.cextern uint8_t flag;int main(){    Timer14_Initial();    GPIO_Initial();    while (1)    {        if(flag == 1)        {            flag = 0;            GPIO_SetBits(GPIOC, GPIO_Pin_8);        }        else        {            GPIO_ResetBits(GPIOC, GPIO_Pin_8);        }    }}stm32f0xx_it.cuint16_t Capture_Timer14 = 0;uint8_t flag = 0;void TIM14_IRQHandler(void){    static uint8_t CC1_Cnt = 0;    if (TIM_GetITStatus(TIM14, TIM_IT_CC1) != RESET)    {        TIM_ClearITPendingBit(TIM14, TIM_IT_CC1);        Capture_Timer14 = TIM_GetCapture1(TIM14);        TIM_SetCompare1(TIM14, Capture_Timer14 + TIM14_CCR_VAL);        if(++CC1_Cnt >= 10){            CC1_Cnt = 0;            flag = 1;        }    }}Timer.c&sharpdefine TIM14_CCR_VAL 1000void Timer14_Initial(void){    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;    TIM_OCInitTypeDef  TIM_OCInitStructure;    NVIC_InitTypeDef NVIC_InitStructure;    uint16_t PrescalerValue = 0;    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14, ENABLE);        PrescalerValue = (uint16_t)((SystemCoreClock)/1000000)-1;    /* Time base configuration */    TIM_TimeBaseStructure.TIM_Period = 65535;    TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;    TIM_TimeBaseStructure.TIM_ClockDivision = 0;    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;    TIM_TimeBaseInit(TIM14, &TIM_TimeBaseStructure);    TIM_PrescalerConfig(TIM14, PrescalerValue, TIM_PSCReloadMode_Immediate);    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;    TIM_OCInitStructure.TIM_Pulse = TIM14_CCR_VAL;    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;    TIM_OC1Init(TIM14, &TIM_OCInitStructure);                   TIM_OC1PreloadConfig(TIM14, TIM_OCPreload_Disable);    TIM_ITConfig(TIM14, TIM_IT_CC1, ENABLE);    TIM_Cmd(TIM14, ENABLE);    NVIC_InitStructure.NVIC_IRQChannel = TIM14_IRQn;    NVIC_InitStructure.NVIC_IRQChannelPriority = 0;    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;    NVIC_Init(&NVIC_InitStructure);} #timer

[Tesla DeLorean]

Posted on July 05, 2016 at 14:29

Not sure exactly what's going on here, but your variable needs to be volatile. I'd recommend toggling the GPIO at each event.

[Walid FTITI_O]

Posted on July 05, 2016 at 15:26

Hi Ben,

Even I don't know why you are waiting 10 times to set the flags in the IRQ_Handler, you should ensure that the declaration ofCCR variable in stm32f0xx_it.c fileas follow:

extern __IO uint16_t TIM14_CCR_VAL;

-Hannibal-

[Radosław]

Posted on July 05, 2016 at 15:44

Hannibal do you think??? TIM14_CCR_VAL is macro.

Only flag variable nedd to be volatile. But anyway this code is mess.  TIM14_CCR_VAL isn't visiblefor all files where is used. So this code will never compile succesfull.

[Walid FTITI_O]

Posted on July 05, 2016 at 16:53

Hi , you would change it to a volatile vaiable.

To get more help, I recommend to get a look to ''TIM_TimeBase'' example in

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-embedded-software/stm32cubef0.html

at this path STM32Cube_FW_F0_V1.2.0\Projects\STM32072B_EVAL\Examples\TIM\TIM_TimeBase You can aslo use

http://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-configurators-and-code-generators/stm32cubemx.html

tool to generate correctly your initialization code and start you project development. -Hannibal-

[Tesla DeLorean]

Posted on July 05, 2016 at 18:44

The OP is clearly not using HAL/Cube. Examples exist within the SPL, and on the forum.

I'd test this by toggling a GPIO, and not having it running under a debugger. I'm not sure why the trace has missing pulses, but I'm not willing to spend my time diagnosing it.

[countach]

Posted on July 06, 2016 at 10:22

Hi clive1, Hannibal and dembek.radoslaw.001

I make a mistake in TIM14_CCR_VAL.It should be set volatile not define in a file. (But, IAR don't show any error or warning before change the variable).After that, it still lose the pulse waveform(I used the example code from en.stsw-stm32140).Thank you for your reply.