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#include <stdio.h>
#include <stm32f4xx.h>
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "systick.h"
#include "rtc.h"
machine_uint_t rtc_info;
#define RTC_INFO_USE_EXISTING (0)
#define RTC_INFO_USE_LSE (1)
#define RTC_INFO_USE_LSI (3)
void rtc_init(void) {
// Enable the PWR clock
RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
// Allow access to RTC
PWR_BackupAccessCmd(ENABLE);
if (RTC_ReadBackupRegister(RTC_BKP_DR0) == 0x32F2) {
// RTC still alive, so don't re-init it
// wait for RTC APB register synchronisation
RTC_WaitForSynchro();
rtc_info = RTC_INFO_USE_EXISTING;
return;
}
uint32_t timeout = 10000000;
// Enable the PWR clock
RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
// Allow access to RTC
PWR_BackupAccessCmd(ENABLE);
// Enable the LSE OSC
RCC_LSEConfig(RCC_LSE_ON);
// Wait till LSE is ready
machine_uint_t sys_tick = sys_tick_counter;
while((RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET) && (--timeout > 0)) {
}
// record how long it took for the RTC to start up
rtc_info = (sys_tick_counter - sys_tick) << 2;
// If LSE timed out, use LSI instead
if (timeout == 0) {
// Disable the LSE OSC
RCC_LSEConfig(RCC_LSE_OFF);
// Enable the LSI OSC
RCC_LSICmd(ENABLE);
// Wait till LSI is ready
while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {
}
// Use LSI as the RTC Clock Source
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);
// record that we are using the LSI
rtc_info |= RTC_INFO_USE_LSI;
} else {
// Use LSE as the RTC Clock Source
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
// record that we are using the LSE
rtc_info |= RTC_INFO_USE_LSE;
}
// Note: LSI is around (32KHz), these dividers should work either way
// ck_spre(1Hz) = RTCCLK(LSE) /(uwAsynchPrediv + 1)*(uwSynchPrediv + 1)
uint32_t uwSynchPrediv = 0xFF;
uint32_t uwAsynchPrediv = 0x7F;
// Enable the RTC Clock
RCC_RTCCLKCmd(ENABLE);
// Wait for RTC APB registers synchronisation
RTC_WaitForSynchro();
// Configure the RTC data register and RTC prescaler
RTC_InitTypeDef RTC_InitStructure;
RTC_InitStructure.RTC_AsynchPrediv = uwAsynchPrediv;
RTC_InitStructure.RTC_SynchPrediv = uwSynchPrediv;
RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24;
RTC_Init(&RTC_InitStructure);
// Set the date (BCD)
RTC_DateTypeDef RTC_DateStructure;
RTC_DateStructure.RTC_Year = 0x13;
RTC_DateStructure.RTC_Month = RTC_Month_October;
RTC_DateStructure.RTC_Date = 0x26;
RTC_DateStructure.RTC_WeekDay = RTC_Weekday_Saturday;
RTC_SetDate(RTC_Format_BCD, &RTC_DateStructure);
// Set the time (BCD)
RTC_TimeTypeDef RTC_TimeStructure;
RTC_TimeStructure.RTC_H12 = RTC_H12_AM;
RTC_TimeStructure.RTC_Hours = 0x01;
RTC_TimeStructure.RTC_Minutes = 0x53;
RTC_TimeStructure.RTC_Seconds = 0x00;
RTC_SetTime(RTC_Format_BCD, &RTC_TimeStructure);
// Indicator for the RTC configuration
RTC_WriteBackupRegister(RTC_BKP_DR0, 0x32F2);
}
/******************************************************************************/
// Micro Python bindings
mp_obj_t pyb_rtc_info(void) {
return mp_obj_new_int(rtc_info);
}
MP_DEFINE_CONST_FUN_OBJ_0(pyb_rtc_info_obj, pyb_rtc_info);
mp_obj_t pyb_rtc_read(void) {
RTC_TimeTypeDef RTC_TimeStructure;
RTC_GetTime(RTC_Format_BIN, &RTC_TimeStructure);
printf("%02d:%02d:%02d\n", RTC_TimeStructure.RTC_Hours, RTC_TimeStructure.RTC_Minutes, RTC_TimeStructure.RTC_Seconds);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_0(pyb_rtc_read_obj, pyb_rtc_read);
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