Question
I could not set the RTC alarm A second time
Hi,
I am using STM32f429II processor. In my application I need to trigger the RTC in 1hr,2hr,3hr,4 hr intervals. So i decided to use RTC alarm A. For testing purpose, I set a 10 secs interval from the current time into alarm register. But it always triggers the alarm IRQ only once. If I reconfigure the the alarm and read the alarm register, still i could view the old values. The new alarm values didn't write into the RTC registers. Please help me to solve this issue.
void SetlogInterval (AirflowInterval_t Interval)
{
NVIC_InitTypeDef NVIC_InitStructure;
TF_Flag_t Status = FALSE;
RTC_TimeTypeDef Current_Time;
RTC_DateTypeDef Current_Date;
RTC_TimeTypeDef Alarm_Time;
RTC_AlarmTypeDef AlarmValue;
//------------------------------------------------------------------------------------------------------
RTC_GetTime(RTC_Format_BIN, &Current_Time);
RTC_GetDate(RTC_Format_BIN, &Current_Date);
//------------------------------------------------------------------------------------------------------
/* EXTI configuration */
EXTI_ClearITPendingBit(EXTI_Line17);
EXTI_InitStructure.EXTI_Line = EXTI_Line17;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = RTC_Alarm_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// NVIC_EnableIRQ(RTC_Alarm_IRQn);
NVIC_DisableIRQ(RTC_Alarm_IRQn);
RTC_GetAlarm(RTC_Format_BIN,RTC_Alarm_A,&AlarmValue); // Read the Alarm Register
value
AlarmValue.RTC_AlarmTime.RTC_H12 = Current_Time.RTC_H12;
AlarmValue.RTC_AlarmTime.RTC_Hours = Current_Time.RTC_Hours;
AlarmValue.RTC_AlarmTime.RTC_Minutes = Current_Time.RTC_Minutes;
AlarmValue.RTC_AlarmTime.RTC_Seconds = Current_Time.RTC_Seconds + 10; // add 10 sec interval
AlarmValue.RTC_AlarmDateWeekDaySel = RTC_AlarmDateWeekDaySel_Date;
AlarmValue.RTC_AlarmDateWeekDay = Current_Date.RTC_Date;
AlarmValue.RTC_AlarmMask = RTC_AlarmMask_DateWeekDay;
/* Makes the DBP bit of PWR_CR register write accessible */
RCC_APB1PeriphResetCmd(RCC_APB1Periph_PWR, DISABLE);
RTC_WriteProtectionCmd(DISABLE);
Status = RTC_AlarmCmd(RTC_Alarm_A, DISABLE);
Status = RTC_AlarmCmd(RTC_Alarm_B, DISABLE);
PWR_BackupAccessCmd(ENABLE);
RTC_SetAlarm(RTC_Format_BIN,RTC_Alarm_A,&AlarmValue);
// for veryfiaction
RTC_GetAlarm(RTC_Format_BIN,RTC_Alarm_A,&AlarmValue); // read the new value
/* Enable RTC Alarm A Interrupt */
RTC_ITConfig(RTC_IT_ALRA, ENABLE);
/* Enable the alarm */
Status = RTC_AlarmCmd(RTC_Alarm_A, ENABLE);
RTC_ClearFlag(RTC_FLAG_ALRAF);
PWR_BackupAccessCmd(DISABLE);
/* Locks the DBP bit of PWR_CR register again */
RCC_APB1PeriphResetCmd(RCC_APB1Periph_PWR, ENABLE);
NVIC_EnableIRQ(RTC_Alarm_IRQn);
}
void RTC_Alarm_IRQHandler(void)
{
if(RTC_GetITStatus(RTC_IT_ALRA) != RESET)
{
RTC_ClearITPendingBit(RTC_IT_ALRA);
EXTI_ClearITPendingBit(EXTI_Line17);
RTC_ClearFlag(RTC_FLAG_ALRAF);
RTC_Alarm_Triggered = TRUE; // this flag call again the SetlogInterval() function to trigger after 10 secs
}
}