My goal is to wake up an MCU that remains in STOP2 Mode. For this i've sucessfully implemented LPTIM to wake-up from STOP2. Now my problem is, that the LPTIM can only be set to a maximum value of 0xFFFF, which is 2 Seconds if i got the stm32 documentation right
But i need a really long time (like 30s)
I'm using the follwing code
Function:
**
* @brief Start the Timeout function in interrupt mode.
* @note The first trigger event will start the timer, any successive
* trigger event will reset the counter and the timer restarts.
* @param hlptim : LPTIM handle
* @param Period : Specifies the Autoreload value.
* This parameter must be a value between 0x0000 and 0xFFFF.
* @param Timeout : Specifies the TimeOut value to rest the counter.
* This parameter must be a value between 0x0000 and 0xFFFF.
* @retval HAL status
*/
HAL_StatusTypeDef HAL_LPTIM_TimeOut_Start_IT(LPTIM_HandleTypeDef *hlptim, uint32_t Period, uint32_t Timeout)
Call:
HAL_LPTIM_TimeOut_Start_IT(&lptim1, 64001, 32000 );
Config:
lptim1.Instance = LPTIM1;
lptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
lptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV1;
lptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
lptim1.Init.Trigger.ActiveEdge = LPTIM_ACTIVEEDGE_RISING;
lptim1.Init.Trigger.SampleTime = LPTIM_TRIGSAMPLETIME_DIRECTTRANSITION;
lptim1.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
lptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
lptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
lptim1.Init.Input1Source = LPTIM_INPUT1SOURCE_GPIO;
lptim1.Init.Input2Source = LPTIM_INPUT2SOURCE_GPIO;
/* Initialize LPTIM peripheral according to the passed parameters */
if (HAL_LPTIM_Init(&lptim1) != HAL_OK)
{
Error_Handler();
}
Source:
PeriphClkInit.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSI; //32kHz LSI
Does anyone has a solution to implement very long times directly? Not via a function that count interrupts or so, because this will cause a wakeup (current increase) each seconds
