Hi,
you can use the integrated lpm module with some extensions. I for myself implemented the STOP2 mode in app_entry.c. Any interrupt will wake the µController again and it will continue until UTIL is idle again. This includes the timer interrupts that the BLE stack uses to advertise or establish a connection.
void UTIL_SEQ_Idle(void)
{
#ifdef DEBUG
return;
#else
/* In case of debugger probe attached, work-around of issue specified in "ES0394 - STM32WB55Cx/Rx/Vx device errata":
2.2.9 Incomplete Stop 2 mode entry after a wakeup from debug upon EXTI line 48 event
"With the JTAG debugger enabled on GPIO pins and after a wakeup from debug triggered by an event on EXTI
line 48 (CDBGPWRUPREQ), the device may enter in a state in which attempts to enter Stop 2 mode are not fully
effective ..."
*/
LL_EXTI_DisableIT_32_63(LL_EXTI_LINE_48);
LL_C2_EXTI_DisableIT_32_63(LL_EXTI_LINE_48);
HAL_SuspendTick();
UTIL_LPM_ENTER_CRITICAL_SECTION( );
PWR_EnterStop2Mode();
// --> here it stops
PWR_ExitStop2Mode();
UTIL_LPM_EXIT_CRITICAL_SECTION( );
/* Configure the system clock for the RUN mode */
/* Resume Tick interrupt if disabled prior to Low Power Sleep mode entry */
HAL_ResumeTick();
return;
#endif
}
You can probably get rid of the HAL_SuspendTick() and HAL_ResumeTick() since the clock is stopped anyway.
void PWR_EnterStop2Mode( void )
{
/* USER CODE BEGIN PWR_EnterStopMode */
/**
* This function is called from CRITICAL SECTION
*/
while( LL_HSEM_1StepLock( HSEM, CFG_HW_RCC_SEMID ) );
if ( ! LL_HSEM_1StepLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID ) )
{
if( LL_PWR_IsActiveFlag_C2DS( ) )
{
/* Release ENTRY_STOP_MODE semaphore */
LL_HSEM_ReleaseLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID, 0 );
/**
* The switch on HSI before entering Stop Mode is required on Cut2.0
* It is useless from Cut2.1
*/
Switch_On_HSI( );
}
}
else
{
/**
* The switch on HSI before entering Stop Mode is required on Cut2.0
* It is useless from Cut2.1
*/
Switch_On_HSI( );
}
/* Release RCC semaphore */
LL_HSEM_ReleaseLock( HSEM, CFG_HW_RCC_SEMID, 0 );
/************************************************************************************
* ENTER STOP MODE
***********************************************************************************/
LL_PWR_SetPowerMode( LL_PWR_MODE_STOP2 );
LL_LPM_EnableDeepSleep( ); /**< Set SLEEPDEEP bit of Cortex System Control Register */
/**
* This option is used to ensure that store operations are completed
*/
#if defined ( __CC_ARM)
__force_stores( );
#endif
__WFI();
/* USER CODE END PWR_EnterStopMode */
}
void PWR_ExitStop2Mode( void )
{
/* USER CODE BEGIN PWR_ExitStopMode */
/**
* This function is called from CRITICAL SECTION
*/
/* Release ENTRY_STOP_MODE semaphore */
LL_HSEM_ReleaseLock( HSEM, CFG_HW_ENTRY_STOP_MODE_SEMID, 0 );
while( LL_HSEM_1StepLock( HSEM, CFG_HW_RCC_SEMID ) );
if(LL_RCC_GetSysClkSource( ) == LL_RCC_SYS_CLKSOURCE_STATUS_HSI)
{
LL_RCC_HSE_Enable( );
while(!LL_RCC_HSE_IsReady( ));
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSE);
while (LL_RCC_GetSysClkSource( ) != LL_RCC_SYS_CLKSOURCE_STATUS_HSE);
}
else
{
/**
* As long as the current application is fine with HSE as system clock source,
* there is nothing to do here
*/
}
/* Release RCC semaphore */
LL_HSEM_ReleaseLock( HSEM, CFG_HW_RCC_SEMID, 0 );
/* USER CODE END PWR_ExitStopMode */
}
static void Switch_On_HSI( void )
{
LL_RCC_HSI_Enable( );
while(!LL_RCC_HSI_IsReady( ));
LL_RCC_SetSysClkSource( LL_RCC_SYS_CLKSOURCE_HSI );
LL_RCC_SetSMPSClockSource(LL_RCC_SMPS_CLKSOURCE_HSI);
while (LL_RCC_GetSysClkSource( ) != LL_RCC_SYS_CLKSOURCE_STATUS_HSI);
}
