Timer interrupt

nanayakkaraan · ‎2010-10-20

Posted on October 20, 2010 at 11:55

Timer interrupt

lowpowermcu · ‎2011-05-17

Posted on May 17, 2011 at 14:11

Hi ANN and andy,

If you want to use TIM4 instead of TIM1, there is some differencies:

- TIM4 is on APB1 and not on APB2

- no repetition counter in TIM4 so no field TIM_RepetitionCounter in timer struct

- interrupt handler is ''TIM4_IRQHandler'' and not ''TIM1_UP_IRQHandler''

That is what I have actually in mind.

regards,

MCU Lüfter

andy239955_stm1_stmicro_com · ‎2011-05-17

Posted on May 17, 2011 at 14:11

Hi ANN,

I have some bits using TIM1 on a ST..103.. that may help. These use the standard libraries.

Put this somewhere in your main.

NVIC_InitTypeDef NVIC_InitStructure;

TIM1_TimeBaseInitTypeDef TIM1_TimeBaseInitStruct;

RCC_APB2PeriphClockCmd (RCC_APB2Periph_TIM1, ENABLE);

// Set timer1

TIM1_TimeBaseInitStruct.TIM1_Prescaler = 8;

TIM1_TimeBaseInitStruct.TIM1_CounterMode = TIM1_CounterMode_Up;

TIM1_TimeBaseInitStruct.TIM1_Period = 10000;

TIM1_TimeBaseInitStruct.TIM1_ClockDivision = TIM1_CKD_DIV1;

TIM1_TimeBaseInitStruct.TIM1_RepetitionCounter = 0;

TIM1_TimeBaseInit (&TIM1_TimeBaseInitStruct);

NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 9;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init (&NVIC_InitStructure);

TIM1_ClearITPendingBit (TIM1_FLAG_Update); // Clear Interrupt

TIM1_ITConfig (TIM1_FLAG_Update, ENABLE); // Enable Interrupt

TIM1_Cmd (ENABLE); // Enable Timer

This next bit assumes a static variable called led_timer initialised to 0, that your LED is on port b and GPIO_LED is defined as the pin your LED is on.

Find TIM1_UP_IRQHandler() in stm32f10x_it.c and put the following code there :-

void TIM1_UP_IRQHandler(void)

{

TIM1_ClearITPendingBit (TIM1_FLAG_Update);

led_timer=1-led_timer;

if (led_timer)

GPIO_ResetBits (GPIOB, GPIO_LED);

else

GPIO_SetBits (GPIOB, GPIO_LED);

}

That should get you a timer interrupt ticking. Play with the Period and Prescaler to get it running at the right speed.

Sorry if it's a bit of a hack, I've taken it from bits of code I have and tied it together. Hopefully it will be enough to get you going.

Cheers,

vmtetons · ‎2011-05-17

Posted on May 17, 2011 at 14:11

Hi ANN

Could you please let me know where you got your STM32L152 devices or board from. I do not seem to find any distributor here in the US for teh low power family.

Thanks

stmdesi

lowpowermcu · ‎2011-05-17

Posted on May 17, 2011 at 14:11

Hi ANN,

I have looked for the site dedicated to STM32L family and I diidn't find eval board documentation neither ST library.

I have found only reference manual ,datasheet and 2 application notes.

Perhaps STM32L152-EVAL isn't from ST. could you trell us where to find it in Germany ?

Thanks ANN,

Herzlich,

MCU Lüfter