Solved
STM32L432KC RTC wakeup from STOP1 mode not working.
The processor never wakes up from STOP1 mode and I do not know why.
Reading RTC time and date works, so I know the RTC clock is running. With debugger (using HAL_EnableDBGStopmode()), I notice that the firmware is stuck in __WFI()
I'm using STM32Cube_FW_L4_V1.13.0
static void deepsleep(uint32_t intervalms)
{
__HAL_RCC_PWR_CLK_ENABLE(); // Enable Power Control clock
HAL_RTCEx_BKUPWrite(&hrtc, RTC_BKP_DR1, 0x32F2);
HAL_NVIC_EnableIRQ(RTC_WKUP_IRQn);
if (HAL_RTCEx_DeactivateWakeUpTimer(&hrtc) != HAL_OK) {
Error_Handler();
}
// clear wake up flags
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);
__HAL_RTC_WAKEUPTIMER_CLEAR_FLAG(&hrtc, RTC_FLAG_WUTF);
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WUFI);
uint32_t _time = (intervalms * 2314) / 1000;
if (HAL_RTCEx_SetWakeUpTimer_IT(&hrtc, _time, RTC_WAKEUPCLOCK_RTCCLK_DIV16) != HAL_OK) {
Error_Handler();
}
HAL_SuspendTick();
HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
// Issue: remains stuck in __WFI(), never wakes up
HAL_ResumeTick();
// Reinit clocks
SystemClock_Config();
// Deactivate RTC wakeUp
if (HAL_RTCEx_DeactivateWakeUpTimer(&hrtc) != HAL_OK) {
Error_Handler();
}
}
int main(void)
{
HAL_Init();
SystemClock_Config();
// For debugging:
HAL_EnableDBGStopMode();
MX_GPIO_Init();
MX_RTC_Init();
while (1)
{
HAL_GPIO_WritePin(LD3_GPIO_Port, LD3_Pin, GPIO_PIN_SET);
HAL_Delay(1000);
HAL_GPIO_WritePin(LD3_GPIO_Port, LD3_Pin, GPIO_PIN_RESET);
deepsleep(1000);
}
}
**
* @brief RTC Initialization Function
* @param None
* @retval None
*/
static void MX_RTC_Init(void)
{
/* USER CODE BEGIN RTC_Init 0 */
/* USER CODE END RTC_Init 0 */
RTC_TimeTypeDef sTime = {0};
RTC_DateTypeDef sDate = {0};
/* USER CODE BEGIN RTC_Init 1 */
/* USER CODE END RTC_Init 1 */
/** Initialize RTC Only
*/
hrtc.Instance = RTC;
hrtc.Init.HourFormat = RTC_HOURFORMAT_24;
hrtc.Init.AsynchPrediv = 127;
hrtc.Init.SynchPrediv = 255;
hrtc.Init.OutPut = RTC_OUTPUT_DISABLE;
hrtc.Init.OutPutRemap = RTC_OUTPUT_REMAP_NONE;
hrtc.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
if (HAL_RTC_Init(&hrtc) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN Check_RTC_BKUP */
/* USER CODE END Check_RTC_BKUP */
/** Initialize RTC and set the Time and Date
*/
sTime.Hours = 0x0;
sTime.Minutes = 0x0;
sTime.Seconds = 0x0;
sTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
sTime.StoreOperation = RTC_STOREOPERATION_RESET;
if (HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BCD) != HAL_OK)
{
Error_Handler();
}
sDate.WeekDay = RTC_WEEKDAY_MONDAY;
sDate.Month = RTC_MONTH_JANUARY;
sDate.Date = 0x1;
sDate.Year = 0x0;
if (HAL_RTC_SetDate(&hrtc, &sDate, RTC_FORMAT_BCD) != HAL_OK)
{
Error_Handler();
}
/** Enable the WakeUp
*/
if (HAL_RTCEx_SetWakeUpTimer(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16) != HAL_OK)
{
Error_Handler();
}
}