rtc.h File Reference

RTC functionality for high-precision logging voltage/current meter. More...

#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	RTC_dateTime_t

Macros
#define	JULIAN_DATE_BASE   2440588

Functions
void	RTC_Init (void)
	Function to initialize the Real Time Clock. More...
void	readFromRTC (void)
	Function to update the RTC data in the struct. More...
void	writeToRTC (void)
	Function to update the RTC values according to the data in the struct. More...

Variables
struct RTC_dateTime_t	rtc

Detailed Description

RTC functionality for high-precision logging voltage/current meter.

Version

1.0

Author

Brecht Van Eeckhoudt

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Versions

• v1.0: Initial version.

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License

Copyright (C) 2021 - Brecht Van Eeckhoudt

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

A copy of the GNU General Public License can be found in the LICENSE file along with this source code.

Definition in file rtc.h.

Macro Definition Documentation

JULIAN_DATE_BASE

#define JULIAN_DATE_BASE   2440588

Unix epoch time in Julian calendar (UnixTime = 00:00:00 01.01.1970 => JDN = 2440588)

Definition at line 47 of file rtc.h.

Function Documentation

readFromRTC()

void readFromRTC

(

void

)

Function to update the RTC data in the struct.

Definition at line 309 of file rtc.c.

{
    RTCcounter_to_dateTime(LL_RTC_TIME_Get(RTC));
}

RTC_Init()

void RTC_Init

(

void

)

Function to initialize the Real Time Clock.

Definition at line 97 of file rtc.c.

{
    /* Enable the PWR Clock and access to the backup domain */
    LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
    LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_BKP);
    LL_PWR_EnableBkUpAccess();
 
    /* Enable LSE only if disabled.*/
    if (LL_RCC_LSE_IsReady() != 1)
    {
        LL_RCC_ForceBackupDomainReset();
        LL_RCC_ReleaseBackupDomainReset();
        LL_RCC_LSE_Enable();
 
        Timeout = LSE_TIMEOUT_VALUE;
 
        while (LL_RCC_LSE_IsReady() != 1)
        {
            if (LL_SYSTICK_IsActiveCounterFlag()) Timeout --;
 
            if (Timeout == 0) while(1); /* LSE activation error */
        }
    }
 
    /* Set LSE as the clock source for the RTC if not already the case */
    if (LL_RCC_GetRTCClockSource() != LL_RCC_RTC_CLKSOURCE_LSE)
    {
        LL_RCC_SetRTCClockSource(LL_RCC_RTC_CLKSOURCE_LSE);
    }
 
    /* Enable RTC peripheral Clock */
    LL_RCC_EnableRTC();
 
 
    /* Disable RTC registers write protection */
    LL_RTC_DisableWriteProtection(RTC);
 
    /* Enter in initialization mode */
    if (LL_RTC_EnterInitMode(RTC) != 0)
    {
        while(1); /* Initialization Error */
    }
 
    /* Configure RTC prescaler, set Asynch Prediv value according to source clock */
    LL_RTC_SetAsynchPrescaler(RTC, RTC_ASYNCH_PREDIV);
 
    /* RTC_Alarm Interrupt Configuration: EXTI configuration */
    LL_EXTI_EnableIT_0_31(LL_EXTI_LINE_17);
    LL_EXTI_EnableRisingTrig_0_31(LL_EXTI_LINE_17);
 
    /* Configure the NVIC for RTC Alarm */
    NVIC_SetPriority(RTC_IRQn, 0);
    NVIC_EnableIRQ(RTC_IRQn);
 
    /* Enable Second Interrupt */
    LL_RTC_EnableIT_SEC(RTC);
 
    /* Exit of initialization mode */
    LL_RTC_ExitInitMode(RTC);
 
    /* Enable RTC registers write protection */
    LL_RTC_EnableWriteProtection(RTC);
 
 
    /* Signal logic so the hour/min/second fields have to be converted to chars after RTC initialization (~boot) */
    rtc.firstUpdate = 1;
}

writeToRTC()

void writeToRTC

(

void

)

Function to update the RTC values according to the data in the struct.

Definition at line 319 of file rtc.c.

{
    /* Disable RTC registers write protection */
    LL_RTC_DisableWriteProtection(RTC);
 
    /* Enter in initialization mode */
    if (LL_RTC_EnterInitMode(RTC) != 0)
    {
        while(1); /* Initialization Error */
    }
 
    /* Set time and date according to struct values, which have been converted to onee uint32_t value */
    LL_RTC_TIME_SetCounter(RTC, dateTime_to_RTCcounter());
 
    /* Clear RSF flag */
    LL_RTC_ClearFlag_RS(RTC);
 
    Timeout = RTC_TIMEOUT_MS;
 
    /* Wait until the RTC Time and Date registers (RTC_TR and RTC_DR) are synchronized with RTC APB clock */
    while(LL_RTC_IsActiveFlag_RS(RTC) != 1)
    {
        if (LL_SYSTICK_IsActiveCounterFlag()) Timeout --;
 
        if (Timeout == 0) while(1); /* Initialization Error */
    }
 
    /* Exit of initialization mode */
    if (LL_RTC_ExitInitMode(RTC) != 0)
    {
        while(1); /* Initialization Error */
    }
 
    /* Enable RTC registers write protection */
    LL_RTC_EnableWriteProtection(RTC);
}

Variable Documentation

rtc

struct RTC_dateTime_t rtc