5 minute Timer (LPTIM1) STM32L073

[Simon NOWAK]

Posted on March 30, 2018 at 10:33

Hi everyone, 

I would like to use LPTIM1 on my STM32L0 to make it wake up (the micro is in Stop Mode) after 5 minutes but I don't know what is the best configuration to do that. Currently I have the configuration below.

&sharpinclude 'Lib_Timer.h'

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

LPTIM_HandleTypeDef lptimHandle;

uint32_t cptCallBack = 0;

/* LPTIM1 init function */

void MX_LPTIM1_Init(void){

lptimHandle.Instance = LPTIM1;

lptimHandle.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC; lptimHandle.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV128; lptimHandle.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE; lptimHandle.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH; lptimHandle.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE; lptimHandle.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL; if (HAL_LPTIM_Init(&lptimHandle) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

}

void HAL_LPTIM_MspInit(LPTIM_HandleTypeDef* lptimHandle)

{

if(lptimHandle->Instance==LPTIM1)

{       /* USER CODE BEGIN LPTIM1_MspInit 0 */

      /* USER CODE END LPTIM1_MspInit 0 */

      /* LPTIM1 clock enable */       __HAL_RCC_LPTIM1_CLK_ENABLE();

      /* LPTIM1 interrupt Init */

      HAL_NVIC_SetPriority(LPTIM1_IRQn, 0, 0);       HAL_NVIC_EnableIRQ(LPTIM1_IRQn);       /* USER CODE BEGIN LPTIM1_MspInit 1 */

      /* USER CODE END LPTIM1_MspInit 1 */

}

}

void HAL_LPTIM_MspDeInit(LPTIM_HandleTypeDef* lptimHandle)

{

if(lptimHandle->Instance==LPTIM1)

{       /* USER CODE BEGIN LPTIM1_MspDeInit 0 */

      /* USER CODE END LPTIM1_MspDeInit 0 */

      /* Peripheral clock disable */       __HAL_RCC_LPTIM1_CLK_DISABLE();

      /* LPTIM1 interrupt Deinit */

      HAL_NVIC_DisableIRQ(LPTIM1_IRQn);       /* USER CODE BEGIN LPTIM1_MspDeInit 1 */

      /* USER CODE END LPTIM1_MspDeInit 1 */

}

}

void Start_Counter(uint32_t period){

      HAL_LPTIM_TimeOut_Start_IT(&lptimHandle, period, 0x0F);}

void Stop_Counter( void ){

      HAL_LPTIM_Counter_Stop_IT(&lptimHandle);}

uint32_t Read_Counter( void ){

      return HAL_LPTIM_ReadCounter(&lptimHandle);}

void HAL_LPTIM_CompareMatchCallback(LPTIM_HandleTypeDef *hlptim){

      cptCallBack++;}

uint32_t get_cptCallBack( void ){

      return cptCallBack;}

I don't know if I use the good callback and the good configuration, currently my callback increase my counter each second, it's too fast (when I call '

Start_Counter' I put period = 0xFFFFF).

Have you any ideas or advices ?

Thank's a lot

Regards

Simon#deepsleep #stm32l073 #stm32l073rz #lptim #stopmode

[RomainR.]

Posted on March 30, 2018 at 12:00

Hello Simon

You can take a look into your local Cube repository for STOP with RTC autowakeup example:

\STM32Cube_FW_L0_V1.10.0\Projects\STM32L073RZ-Nucleo\Examples\PWR\PWR_STOP_RTC

Regards,

[waclawek.jan]

Posted on March 30, 2018 at 13:51

lptimHandle.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;

lptimHandle.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV128;

So, as it appears that you did not change the default value of RCC_CCIPR.LPTIM1SEL,  what's your APB clock frequency? Divide that by 128 and the autoreload value, which is

it's too fast (when I call '

Start_Counter' I put period = 0xFFFFF)

oh, the LPTIM is 16-bit only, so you can't set it to 0xFFFFF.

JW

[henry.dick]

Posted on March 30, 2018 at 17:07

take a look at its prescaler and timer width and see if you can achieve the said duration with just the prescaler + timer period.

if not, consider a different timer that can;

if this timer is your only option, set up the mcu to wake up at certain interval, like roll-over. In the isr, increment a counter and test if certain number of roll-overs has been achieved. Essentially that counter forms your most significant bits of the timer.

[helmi haddad]

Posted on June 27, 2018 at 12:50

any idea how i can configure the LPTim for period hour please , and any solution for period in minutes please