Timer interrupt Question

[lizerd]

Posted on November 29, 2010 at 09:31

Timer interrupt Question

[lowpowermcu]

Posted on May 17, 2011 at 14:16

Hi,

You need to configure the time base, enable update interrupt and configure the NVIC. Add     /* TIM update IT enable */   TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE); Remove from configuration: /********    satrt                 *******/   /* Output Compare Timing Mode configuration: Channel1 */   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;   TIM_OCInitStructure.TIM_Pulse = 3000;   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;   TIM_OC1Init(TIM2, &TIM_OCInitStructure);   TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);   /* TIM IT enable */   TIM_ITConfig(TIM2, TIM_IT_CC1, ENABLE); /********   end                 *******/ /* !!!!!!!!!!!!!!!!!!!!! Don't remove this!!!!!!!!!!!!!!!!!!!!!!!!!!! */   /* TIM2 enable counter */   TIM_Cmd(TIM2, ENABLE); In the timer interrupt, as you said you need to clear the interrupt change void TIM2_IRQHandler(void) {   if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)   {     TIM_ClearITPendingBit(TIM2, TIM_IT_CC1);     capture = TIM_GetCapture1(TIM2);     TIM_SetCompare1(TIM2, capture + 3000);      // Main Clock Timer     Timer_mSec++;     if(Timer_mSec == 1000)     {         Timer_mSec = 0;         Timer_Sec++;         if(Timer_Sec == 60)         {             Timer_Sec = 0;             Timer_Min++;         }     }   }   TestTime++; } by void TIM2_IRQHandler(void) {   if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)   {      // Main Clock Timer     Timer_mSec++;     if(Timer_mSec == 1000)     {         Timer_mSec = 0;         Timer_Sec++;         if(Timer_Sec == 60)         {             Timer_Sec = 0;             Timer_Min++;         }     TIM_ClearITPendingBit(TIM2, TIM_IT_Update);   } } Remark:   TIM_OC1Init() configures Output Compare channel: pwm1, pwm2

[Tesla DeLorean]

Posted on May 17, 2011 at 14:16

Third question:

Is this the best way to go for a simple time based interrupt routine ??

Well define ''best''. What period do you want, is it continuous or variable, etc. SysTick is pretty simple. The RTC can go sub-second with the appropriate scale. The TIMx timers can be a lot simpler than you have presented if you just want a constant periodic interrupt ticker.

[Tesla DeLorean]

Posted on May 17, 2011 at 14:16

For the VL Discovery a simple implementation with blinking LEDs

void TIM2_IRQHandler(void) {   if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)   {     TIM_ClearITPendingBit(TIM2, TIM_IT_Update);     /* Whatever */     STM32vldiscovery_LEDToggle(LED3);   } } int main(void) {   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;   NVIC_InitTypeDef NVIC_InitStructure;   /* Initialise LEDs LD3&LD4, both off */   STM32vldiscovery_LEDInit(LED3);   STM32vldiscovery_LEDInit(LED4);   STM32vldiscovery_LEDOff(LED3);   STM32vldiscovery_LEDOff(LED4);   /* Enable the TIM2 gloabal Interrupt */   NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;   NVIC_Init(&NVIC_InitStructure);   /* TIM2 clock enable */   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);   /* VL clocks at 24 MHz, change to 72 - 1 for a 72 MHz system   /* Time base configuration */   TIM_TimeBaseStructure.TIM_Period = 1000 - 1;  // 1 MHz down to 1 KHz (1 ms)   TIM_TimeBaseStructure.TIM_Prescaler = 24 - 1; // 24 MHz Clock down to 1 MHz (adjust per your clock)   TIM_TimeBaseStructure.TIM_ClockDivision = 0;   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;   TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);   /* TIM IT enable */   TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);   /* TIM2 enable counter */   TIM_Cmd(TIM2, ENABLE);   while (1); }

[lizerd]

Posted on May 17, 2011 at 14:16

i am using the SysTick already, so i have learned how to use the SysTick.

But now i trying to master the ''Normal'' Timer interrupt. So right now i trying to find a simple interrupt based on the TIM timers. I have checked and tested some of the timer example. but i did not find any one that is a simple interrupt based timer. Lets say. a timer that go´s into interrupt every 1ms I haven´t tested code yet,