【AT-START-F425 Review】+ ERTC and the implementation of electronic clock

jinglixixi

【AT-START-F425 Review】+ ERTC and the implementation of electronic clock [Copy link]

 

The AT32 F425 is equipped with an RTC timer, which can be used in conjunction with the corresponding functions to realize the RTC timing and timing functions. The operating effect is shown in Figure 1.

Figure 1 Operation effect

If RTC is combined with OLED screen, the function of electronic clock can be easily realized.

Based on the OLED screen display driver introduced above, the main program to achieve the timing effect in Figure 2 is:

int main(void)
{
 exint_init_type exint_init_struct;
 ertc_time_type time;
 uint32_t temp = 0;
 system_clock_config();
  nvic_priority_group_config(NVIC_PRIORITY_GROUP_4);
 at32_board_init();
  crm_periph_clock_enable(CRM_PWC_PERIPH_CLOCK, TRUE);
 pwc_battery_powered_domain_access(TRUE);
 if (ertc_bpr_data_read(ERTC_DT1) != 0x1234)
 {
 ertc_config(); // 设置时间值函数，添加按键参数设置功能！
 }
 else
 {
 ertc_wait_update();
 ertc_flag_clear(ERTC_ALAF_FLAG);
 exint_flag_clear(EXINT_LINE_17);
 }
 exint_default_para_init(&exint_init_struct);
 exint_init_struct.line_enable = TRUE;
 exint_init_struct.line_mode = EXINT_LINE_INTERRUPUT;
 exint_init_struct.line_select = EXINT_LINE_17;
 exint_init_struct.line_polarity = EXINT_TRIGGER_RISING_EDGE;
 exint_init(&exint_init_struct);
 nvic_irq_enable(ERTC_IRQn, 0, 1);
 app_oled_init();
 app_oled_init();
 OLED_Init();
 OLED_Clear();
 OLED_ShowString(8,0,"AT32F425",16);
 OLED_ShowString(8,2,"OLED & RTC",16);
 while(1)
 {
 ertc_calendar_get(&time);
 if(temp != time.sec)
 {
 temp = time.sec;
  sprintf(da_buf,"20%02d-%02d-%02d ",time.year, time.month, time.day);
 OLED_ShowString(8,4,da_buf,16);
   sprintf(da_buf,"%02d:%02d:%02d",time.hour, time.min, time.sec);
  OLED_ShowString(8,6,da_buf,16);
 }
 }
}

The processing flow of the program is:

First, the RTC is initialized, and then the flag variable is identified. If the initial timing value is not set, the initial value in the program is read to count. Otherwise, the timing is processed based on the existing timing value.

Figure 2 Display effect

The initial value of RTC is set in the function ertc_config, and its content is:

hh =12;
nn=0;
ss=0;
void ertc_config(void)
{
 crm_periph_clock_enable(CRM_PWC_PERIPH_CLOCK, TRUE);
 pwc_battery_powered_domain_access(TRUE);
 crm_battery_powered_domain_reset(TRUE);
 crm_battery_powered_domain_reset(FALSE);
#if defined (ERTC_CLOCK_SOURCE_LICK)
 crm_clock_source_enable(CRM_CLOCK_SOURCE_LICK, TRUE);
 while(crm_flag_get(CRM_LICK_STABLE_FLAG) == RESET)
 {
 }
 crm_ertc_clock_select(CRM_ERTC_CLOCK_LICK);
 ertc_clk_div_b = 255;
 ertc_clk_div_a = 127;
#elif defined (ERTC_CLOCK_SOURCE_LEXT)
 crm_clock_source_enable(CRM_CLOCK_SOURCE_LEXT, TRUE);
 while(crm_flag_get(CRM_LEXT_STABLE_FLAG) == RESET)
 {
 }
 crm_ertc_clock_select(CRM_ERTC_CLOCK_LEXT);
 ertc_clk_div_b = 255;
 ertc_clk_div_a = 127;
#endif
 crm_ertc_clock_enable(TRUE);
 ertc_reset();
 ertc_wait_update();
 ertc_divider_set(ertc_clk_div_a, ertc_clk_div_b);
 ertc_hour_mode_set(ERTC_HOUR_MODE_24);
 ertc_date_set(22, 3, 2, 3);
 ertc_time_set(hh ,nn ,ss, ERTC_AM);
 ertc_alarm_mask_set(ERTC_ALA, ERTC_ALARM_MASK_DATE_WEEK);
 ertc_alarm_week_date_select(ERTC_ALA, ERTC_SLECT_DATE);
 ertc_flag_clear(ERTC_ALAF_FLAG);
 ertc_bpr_data_write(ERTC_DT1, 0x1234);
}

To facilitate time synchronization, you can add a key processing function to set parameters.

Since there is only one user key on the development board, it is not convenient for parameter setting, so a membrane key is configured for it, and 3 of the keys can be used. The "1" key is used for -1, the "2" key is used for +1, and the "3" key is used for confirmation.

The connection relationship between the button and the development board is:

key1---PB5

key2---PB3

key3---PA10

GND---PB10

Figure 3 Arduino interface

#define key1 gpio_input_data_bit_read(GPIOB, GPIO_PINS_5)

#define key2 gpio_input_data_bit_read(GPIOB, GPIO_PINS_4)

#define key3 gpio_input_data_bit_read(GPIOA, GPIO_PINS_10)

The corresponding time setting function is:

void time_set(void)
{
 int8_t i=0,n;
 n=hh;
 i=0;
 while (i<3)
 {
 if(key1==0)
 {
 n--;
 }
 if(key2==0)
 {
 n++;
 }
 if(key3==0)
  {
 if(i==0)
 {
 n=mm;
 }
  if(i==1)
 {
 n=ss;
 }
 i++;
  while(key3==0);
 }
 if(i==0)
 {
 hh=n;
 OLED_ShowNum(8,6,hh,2,16);
 }
 if(i==1)
 {
 mm=n;
 OLED_ShowNum(32,6,mm,2,16);
 }
 if(i==2)
 {
 ss=n;
 OLED_ShowNum(56,6,ss,2,16);
 }
 delay_ms(200);
 }
}

Among them, the variable hh stores the time value, the variable mm stores the minute value, and the variable ss stores the second value.

The date setting function can be similar.

wangerxian

ERTC is internal RTC?

jinglixixi

wangerxian posted on 2022-4-6 16:02 Is ERTC an internal RTC?

yes

wangerxian

jinglixixi posted on 2022-4-7 00:10 Yes

This E always feels external.

jinglixixi

wangerxian posted on 2022-4-7 09:35 This E always feels external

That makes sense, but it may be to distinguish it from the so-called soft RTC now!