stm32f401ccu6 hal库 rtc闹钟

要使用STM32F401CCU6的HAL库实现RTC闹钟功能，需要按照以下步骤进行配置：

1. 初始化RTC时钟和备份区域

   RCC_OscInitTypeDef RCC_OscInitStruct;
   RCC_PeriphCLKInitTypeDef RCC_RTCInitStruct;
   HAL_PWR_EnableBkUpAccess();
   __HAL_RCC_PWR_CLK_ENABLE();
   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
   HAL_RCC_OscConfig(&RCC_OscInitStruct);
   RCC_RTCInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RTC;
   RCC_RTCInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
   HAL_RCCEx_PeriphCLKConfig(&RCC_RTCInitStruct);
   __HAL_RCC_RTC_ENABLE();

2. 配置RTC时钟和日期时间格式

   RTC_HandleTypeDef hrtc;
   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.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
   hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
   HAL_RTC_Init(&hrtc);

3. 设置闹钟时间并开启闹钟

   RTC_AlarmTypeDef sAlarm;
   sAlarm.AlarmTime.Hours = 8;
   sAlarm.AlarmTime.Minutes = 0;
   sAlarm.AlarmTime.Seconds = 0;
   sAlarm.AlarmTime.SubSeconds = 0;
   sAlarm.AlarmMask = RTC_ALARMMASK_DATEWEEKDAY;
   sAlarm.AlarmDateWeekDaySel = RTC_ALARMDATEWEEKDAYSEL_DATE;
   sAlarm.AlarmDateWeekDay = 1;
   sAlarm.Alarm = RTC_ALARM_A;
   HAL_RTC_SetAlarm_IT(&hrtc, &sAlarm, RTC_FORMAT_BIN);