[经验分享] 【GD32F350分享】【六】增加RTC时钟功能

hanyeguxingwo 2018-9-21 14:23 楼主

GD32F350的RTC模块提供了一个包含日期（年/月/日）和时间（时/分/秒/亚秒）的日历功能。除亚秒用二进制码显示外，时间和日期都以BCD码的形式显示。RTC可以进行夏令时补偿。RTC可以工作在省电模式下，并通过软件配置来智能唤醒。RTC支持外接更高精度的低频时钟，用以达到更高的日历精度。
这里参考库函数里面的例程对RTC进行了初始化和串口时钟设置，实现实时时钟的功能。再工程目录下的Driver文件夹增加rtc源文件和头文件，同时编写RTC初始化函数，再主函数中通过串口进行时分秒设置。这里使用了BKP_VALUE作为时钟是否初始化过的标志位。

void Init_RTC(void)
{
/* enable PMU clock */
rcu_periph_clock_enable(RCU_PMU);
/* enable the access of the RTC registers */
pmu_backup_write_enable();
rcu_osci_on(RCU_IRC40K);
rcu_osci_stab_wait(RCU_IRC40K);
rcu_rtc_clock_config(RCU_RTCSRC_IRC40K);
prescaler_s = 0x18F;
prescaler_a = 0x63;
rcu_periph_clock_enable(RCU_RTC);
rtc_register_sync_wait();
}
/*!
\brief use hyperterminal to setup RTC time and alarm
\param[in] none
\param[out] none
\retval none
*/
void rtc_setup(void)
{
/* setup RTC time value */
uint32_t tmp_hh = 0xFF, tmp_mm = 0xFF, tmp_ss = 0xFF;
rtc_initpara.rtc_factor_asyn = prescaler_a;
rtc_initpara.rtc_factor_syn = prescaler_s;
rtc_initpara.rtc_year = 0x18;
rtc_initpara.rtc_day_of_week = RTC_FRIDAY;
rtc_initpara.rtc_month = RTC_SEP;
rtc_initpara.rtc_date = 0x21;
rtc_initpara.rtc_display_format = RTC_24HOUR;
rtc_initpara.rtc_am_pm = RTC_AM;
/* current time input */
printf("=======Configure RTC Time========\n\r");
printf(" please input hour:\n\r");
while (tmp_hh == 0xFF){
tmp_hh = usart_input_threshold(23);
rtc_initpara.rtc_hour = tmp_hh;
}
printf(" %0.2x\n\r", tmp_hh);
printf(" please input minute:\n\r");
while (tmp_mm == 0xFF){
tmp_mm = usart_input_threshold(59);
rtc_initpara.rtc_minute = tmp_mm;
}
printf(" %0.2x\n\r", tmp_mm);
printf(" please input second:\n\r");
while (tmp_ss == 0xFF){
tmp_ss = usart_input_threshold(59);
rtc_initpara.rtc_second = tmp_ss;
}
printf(" %0.2x\n\r", tmp_ss);
/* RTC current time configuration */
if(ERROR == rtc_init(&rtc_initpara)){
printf("\n\r** RTC time configuration failed! **\n\r");
}else{
printf("\n\r** RTC time configuration success! **\n\r");
rtc_show_time();
RTC_BKP0 = BKP_VALUE;
}
}
/*!
\brief display the current time
\param[in] none
\param[out] none
\retval none
*/
void rtc_show_time(void)
{
uint32_t time_subsecond = 0;
uint8_t subsecond_ss = 0,subsecond_ts = 0,subsecond_hs = 0;
rtc_current_time_get(&rtc_initpara);
/* get the subsecond value of current time, and convert it into fractional format */
time_subsecond = rtc_subsecond_get();
subsecond_ss=(1000-(time_subsecond*1000+1000)/400)/100;
subsecond_ts=(1000-(time_subsecond*1000+1000)/400)%100/10;
subsecond_hs=(1000-(time_subsecond*1000+1000)/400)%10;
printf("Current time: 20%0.2x-%0.2x-%0.2x %0.2x:%0.2x:%0.2x .%d%d%d \n\r", \
rtc_initpara.rtc_year, rtc_initpara.rtc_month , rtc_initpara.rtc_date,\
rtc_initpara.rtc_hour, rtc_initpara.rtc_minute, rtc_initpara.rtc_second,\
subsecond_ss, subsecond_ts, subsecond_hs);
}
/*!
\brief get the input character string and check if it is valid
\param[in] none
\param[out] none
\retval input value in BCD mode
*/
uint8_t usart_input_threshold(uint32_t value)
{
uint32_t index = 0;
uint32_t tmp[2] = {0, 0};
while (index < 2){
while (RESET == usart_flag_get(USART1, USART_FLAG_RBNE));
tmp[index++] = usart_data_receive(USART1);
if ((tmp[index - 1] < 0x30) || (tmp[index - 1] > 0x39)){
printf("\n\r please input a valid number between 0 and 9 \n\r");
index--;
}
}
index = (tmp[1] - 0x30) + ((tmp[0] - 0x30) * 10);
if (index > value){
printf("\n\r please input a valid number between 0 and %d \n\r", value);
return 0xFF;
}
index = (tmp[1] - 0x30) + ((tmp[0] - 0x30) <<4);
return index;
}