Question
STM32L475 - Problem Reading RTC Time and Date after Wakeup
Posted on November 07, 2016 at 08:54
I'm using the RTC to Wakeup my STM32L475 µC from Standby Mode. That is working fine.
And i use the The HAL Library 1.5.2 for STM32L4 The main problem is i have to read the Time and Date after Wakeup. I use the functions: HAL_RTC_GetTime(&hrtc, &strTimeouts.strLastCheckTime, RTC_FORMAT_BIN); HAL_RTC_GetDate(&hrtc, &strTimeouts.strLastCheckDate, RTC_FORMAT_BIN); I know that i have to read the time first, than the date. And i know that i have to reset the RSF (Register Syncronisation Flag) after Wakeup. Since i don't want to reinit my completet RTC with Date and Time i have made some own Init functions, wich where called after wakeup:/**
* @brief Initialize the RTC according to the specified parameters
* in the RTC_InitTypeDef structure and initialize the associated handle.
* @param hrtc: RTC handle
* @retval HAL status
*/
HAL_StatusTypeDef HAL_RTC_Wakeup_Init(RTC_HandleTypeDef *hrtc)
{
//uint32_t tmpreg = 0;
/* Check the RTC peripheral state */
if(hrtc == NULL)
{
return HAL_ERROR;
}
/* Check the parameters */
assert_param(IS_RTC_ALL_INSTANCE(hrtc->Instance));
assert_param(IS_RTC_HOUR_FORMAT(hrtc->Init.HourFormat));
assert_param(IS_RTC_ASYNCH_PREDIV(hrtc->Init.AsynchPrediv));
assert_param(IS_RTC_SYNCH_PREDIV(hrtc->Init.SynchPrediv));
assert_param(IS_RTC_OUTPUT(hrtc->Init.OutPut));
assert_param(IS_RTC_OUTPUT_REMAP(hrtc->Init.OutPutRemap));
assert_param(IS_RTC_OUTPUT_POL(hrtc->Init.OutPutPolarity));
assert_param(IS_RTC_OUTPUT_TYPE(hrtc->Init.OutPutType));
if(hrtc->State == HAL_RTC_STATE_RESET)
{
/* Allocate lock resource and initialize it */
hrtc->Lock = HAL_UNLOCKED;
/* Initialize RTC MSP */
//HAL_RTC_MspInit(hrtc);
// Abfragen ob RTC Clock bereits aktiviert wurde
if((RCC->BDCR & RCC_BDCR_RTCEN) == (uint32_t)RESET)
{
__HAL_RCC_RTC_ENABLE();
}
HAL_NVIC_SetPriority(RTC_WKUP_IRQn, 6, 0);
HAL_NVIC_EnableIRQ(RTC_WKUP_IRQn);
}
/* Set RTC state */
hrtc->State = HAL_RTC_STATE_BUSY;
/* Disable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_DISABLE(hrtc);
/* Set Initialization mode */
if(RTC_EnterInitMode(hrtc) != HAL_OK)
{
/* Enable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_ENABLE(hrtc);
/* Set RTC state */
hrtc->State = HAL_RTC_STATE_ERROR;
return HAL_ERROR;
}
else
{
/* Clear RTC_CR FMT, OSEL and POL Bits */
hrtc->Instance->CR &= ((uint32_t)~(RTC_CR_FMT | RTC_CR_OSEL | RTC_CR_POL));
/* Set RTC_CR register */
hrtc->Instance->CR |= (uint32_t)(hrtc->Init.HourFormat | hrtc->Init.OutPut | hrtc->Init.OutPutPolarity);
/* Configure the RTC PRER */
hrtc->Instance->PRER = (uint32_t)(hrtc->Init.SynchPrediv);
hrtc->Instance->PRER |= (uint32_t)(hrtc->Init.AsynchPrediv <<
16
);
// Clear RSF Flag after Wakeup
hrtc->Instance->ISR &= ((uint32_t)~RTC_ISR_RSF);
/* Exit Initialization mode */
hrtc->Instance->ISR &= ((uint32_t)~RTC_ISR_INIT);
hrtc->Instance->OR &= (uint32_t)~(RTC_OR_ALARMOUTTYPE | RTC_OR_OUT_RMP);
hrtc->Instance->OR |= (uint32_t)(hrtc->Init.OutPutType | hrtc->Init.OutPutRemap);
/* Enable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_ENABLE(hrtc);
/* Set RTC state */
hrtc->State = HAL_RTC_STATE_READY;
return HAL_OK;
}
}
void MX_RTC_Wakeup_Init(void)
{
//Initialize RTC
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_Wakeup_Init(&hrtc) != HAL_OK)
{
Error_Handler();
}
}