rtc时间精度的问题

只看该作者 · 2017-10-11 15:28

先上代码：
int main(void)
{
  /* USER CODE BEGIN 1 */
  /* USER CODE END 1 */
  /* MCU Configuration----------------------------------------------------------*/
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
  /* USER CODE BEGIN Init */
  /* USER CODE END Init */
  /* Configure the system clock */
  SystemClock_Config();
  /* USER CODE BEGIN SysInit */
  /* USER CODE END SysInit */
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_RTC_Init();
  MX_USART1_UART_Init();
  /* Initialize interrupts */
  MX_NVIC_Init();
gUSER_SendSec_Index = 0x00;
  /* USER CODE BEGIN 2 */
__HAL_UART_CLEAR_IDLEFLAG(&huart1);
__HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);
  /* USER CODE END 2 */
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
  /* USER CODE END WHILE */
  if(gUSER_SendSec_Index == 0x01)
  {
USER_BackInfo();
gUSER_SendSec_Index = 0x00;
  }
  USER_Uart_DmaRecv();
  /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}
//RTC配置
static void MX_RTC_Init(void)
{
  RTC_TimeTypeDef sTime;
  RTC_DateTypeDef sDate;
/**Initialize RTC Only
*/
  hrtc.Instance = RTC;
  hrtc.Init.HourFormat = RTC_HOURFORMAT_24;
  hrtc.Init.AsynchPrediv = 0;
  hrtc.Init.SynchPrediv = 31999;
  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(__FILE__, __LINE__);
  }
/**Initialize RTC and set the Time and Date
*/
  if(HAL_RTCEx_BKUPRead(&hrtc, RTC_BKP_DR0) != 0x32F2){
  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(__FILE__, __LINE__);
  }
  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(__FILE__, __LINE__);
  }
HAL_RTCEx_BKUPWrite(&hrtc,RTC_BKP_DR0,0x32F2);
  }
/**Enable the WakeUp
*/
  if (HAL_RTCEx_SetWakeUpTimer_IT(&hrtc, 0, RTC_WAKEUPCLOCK_RTCCLK_DIV16) != HAL_OK)
  {
_Error_Handler(__FILE__, __LINE__);
  }
}
void HAL_RTCEx_WakeUpTimerEventCallback(RTC_HandleTypeDef *hrtc1)
{
gUSER_SendSec_Index = 0x01;
HAL_RTCEx_SetWakeUpTimer_IT(&hrtc, 0, RTC_WAKEUPCLOCK_CK_SPRE_16BITS);
}
//通过串口发送至PC机显示时间
void USER_BackInfo(void)
{
RTC_TimeTypeDef sTime;
  RTC_DateTypeDef sDate;

gUARTSendBuff[0] = '$';
gUARTSendBuff[1] = 'I';
gUARTSendBuff[2] = 'N';
gUARTSendBuff[3] = 'F';
gUARTSendBuff[4] = 'O';
gUARTSendBuff[5] = 0x00;
gUARTSendBuff[6] = 0x0E;
gUARTSendBuff[7] = ID;
gUARTTx_Len = 14;

HAL_RTC_GetTime(&hrtc, &sTime, RTC_FORMAT_BIN);
  HAL_RTC_GetDate(&hrtc, &sDate, RTC_FORMAT_BIN);

gUARTSendBuff[8] = sDate.Year;
gUARTSendBuff[9] = sDate.Month;
gUARTSendBuff[10] = sDate.Date;
gUARTSendBuff[11] = sTime.Hours;
gUARTSendBuff[12] = sTime.Minutes;
gUARTSendBuff[13] = sTime.Seconds;

USER_Uart_DataSend();

}

在PC机上同时显示PC机时间和通过串口收到的时间，才过了3个小时就差了30秒，这个精度很低呀，是我哪里没弄对么？