【AT32F421 Review】+RTC Electronic Clock

jinglixixi

【AT32F421 Review】+RTC Electronic Clock [Copy link]

 

The AT32F421 is equipped with an RTC timer and is equipped with corresponding routines to assist in learning, use and functional verification.

The verification result of the routine ERTC_Calendar is shown in Figure 1.

Figure 1 RTC verification effect

In order to facilitate intuitive observation, the OLED screen display function introduced earlier can be combined with the RTC, and the display effect is shown in Figure 2.

Figure 2 Clock timing effect

The main program to achieve the timing effect shown in the figure is:

int main(void)
{
  NVIC_InitType NVIC_InitStructure;
   EXTI_InitType EXTI_InitStructure;
  int temp=0;
  AT32_Board_Init();
AT32_OLED_Init();
OLED_Init();
OLED_Clear();
OLED_ShowString(0,0,"AT32F421",16);
OLED_ShowString(0,2,"RTC & OLED",16);
  if (ERTC_ReadBackupRegister(ERTC_BKP_DT0) != 0x32F1)
  {
   ERTC_Config();
   ERTC_TimeShow();
   ERTC_AlarmShow();
  }
   else
  {
   if (RCC_GetFlagStatus(RCC_FLAG_PORST) != RESET)
    {
      AT32_LEDn_ON(LED3);
    }
   else if (RCC_GetFlagStatus(RCC_FLAG_PINRST) != RESET)
   {
      AT32_LEDn_ON(LED4);
    }
   RCC_APB1PeriphClockCmd(RCC_APB1PERIPH_PWR, ENABLE);
   PWR_BackupAccessCtrl(ENABLE);
   ERTC_WaitForSynchro();
   ERTC_ClearFlag(ERTC_FLAG_ALAF);
   EXTI_ClearIntPendingBit(EXTI_Line17);
   ERTC_TimeShow();
   ERTC_AlarmShow();
  }
  EXTI_ClearIntPendingBit(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_LineEnable = ENABLE;
  EXTI_Init(&EXTI_InitStructure);
 NVIC_InitStructure.NVIC_IRQChannel = ERTC_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  OLED_Clear();
 OLED_ShowString(0,0,"20 - -",16);
 OLED_ShowString(0,2," : :",16);
  while (1)
  {
      ERTC_GetTimeValue(ERTC_Format_BIN, &ERTC_TimeStructure);
 ERTC_GetDateValue(ERTC_Format_BIN, &ERTC_DateStructure);
       if(temp != ERTC_TimeStructure.ERTC_Seconds)
      {
      temp = ERTC_TimeStructure.ERTC_Seconds;
       OLED_ShowNum(16,0,ERTC_DateStructure.ERTC_Year,2,16);
  OLED_ShowNum(40,0,ERTC_DateStructure.ERTC_Month,2,16);
  OLED_ShowNum(64,0,ERTC_DateStructure.ERTC_Date,2,16);
  OLED_ShowNum(0,2,ERTC_TimeStructure.ERTC_Hours,2,16);
  OLED_ShowNum(24,2,ERTC_TimeStructure.ERTC_Minutes,2,16);
  OLED_ShowNum(48,2,ERTC_TimeStructure.ERTC_Seconds,2,16);
 }
    }

}

Jacktang

After power off and restart, is the RTC data lost?

jinglixixi

Jacktang posted on 2021-4-27 08:58 Is the RTC data lost after power failure and restart

Without a backup battery to support the RTC, it will definitely be lost

邓佩华

Can you provide a demo zip file?