Class RTC

Description

A class used for displaying date and time and alarm configuration using RTC, the independent BCD (Binary-Coded-Decimal) timer.

Syntax

class RTC

Members

Public Constructors

A public constructor should not be used as this class is intended to be a singleton class. Access member functions using the object instance named RTC.

Public Methods

RTC:: Init

Initializes the RTC device, including the Clock, the RTC registers, and other functions

RTC:: DeInit

Deinitialize the RTC device

RTC:: Write

Set the specified timestamp in seconds to RTC

RTC:: Read

Get the current timestamp in seconds from RTC

RTC:: Wait

Wait for 1 second

RTC:: SetEpoch

Convert human-readable time to epoch time
RTC::Init

Description

Initializes the RTC device, including the Clock, the RTC registers, and other functions.

Syntax

void RTC::Init(void);

Parameters

The function requires no input parameter.

Returns

The function returns nothing.

Example Code

Example: RTC

RTC
 1  /**
 2*  This function describes how to use the RTC API.
 3*  The RTC function is implemented by an independent BCD timer/counter.
 4*  This example will print out the time information every second.
 5*/
 6#include "stdio.h"
 7#include "time.h"
 8
 9#include "rtc.h"
10
11#define YEAR 2020
12#define MONTH 9
13#define DAY 10
14#define HOUR 20
15#define MIN 30
16#define SEC 40
17
18/* Create an rtc object */
19RTC rtc;
20int32_t seconds;
21struct tm *timeinfo;
22
23void setup() {
24    Serial.begin(115200);
25    rtc.Init();  // initialize RTC
26}
27
28void loop() {
29    // step 1: convert user time to epoch
30    int epochTime = humanReadableToEpoch(YEAR, MONTH, DAY, HOUR, MIN, SEC);
31
32    // step 2: write epoch time to rtc
33    rtc.Write(epochTime);
34    while (1) {
35        seconds = rtc.Read();
36        printf("Epoch Time (in s) since January 1, 1970 = %ds\n", seconds);
37        printf("Time as a basic string = %s", ctime(&seconds));
38        timeinfo = localtime(&seconds);
39        printf("Time as a custom formatted string = %d-%d-%d %d:%d:%d\n",
40              (timeinfo->tm_year + 1900), (timeinfo->tm_mon + 1), timeinfo->tm_mday, timeinfo->tm_hour,
41              timeinfo->tm_min, timeinfo->tm_sec);
42        Serial.println();
43        rtc.wait(1);
44    }
45}
46
47// convert human readable time to epoch time
48int humanReadableToEpoch(int year, int month, int day, int hour, int min, int sec) {
49    struct tm t;
50    time_t t_of_day;
51
52    t.tm_year = year - 1900;  // Year - 1970
53    t.tm_mon = month - 1;     // Month, where 0 = jan
54    t.tm_mday = day;          // Day of the month
55    t.tm_hour = hour;
56    t.tm_min = min;
57    t.tm_sec = sec;
58    t.tm_isdst = -1;  // Is DST on? 1 = yes, 0 = no, -1 = unknown
59    t_of_day = mktime(&t);
60
61    // printf("seconds since the Epoch: %d\n", (long)t_of_day);
62    return t_of_day;
63}

Notes and Warnings

NA

RTC::DeInit

Description

Deinitializes the RTC device.

Syntax

void RTC::DeInit(void);

Parameters

The function requires no input parameter.

Returns

The function returns nothing.

Example Code

Example: RTC

Details of the code can be found in the previous section of RTC::Init.

Notes and Warnings

NA

RTC:: Write

Description

Set the specified timestamp in seconds to RTC. Seconds from 1970.1.1 00:00:00 (YEAR.MONTH.DAY, HOUR: MIN: SECONDS) to specified date and time which is to be set.

Syntax

void RTC::Write(int t);

Parameters

t : Seconds from 1970.1.1 00:00:00 (YEAR.MONTH.DAY, HOUR: MIN: SECONDS) to specified date and time which is to be set.

Returns

The function returns nothing.

Example Code

Example: RTC

Details of the code can be found in the previous section of RTC::Init.

Notes and Warnings

NA

RTC::Read

Description

Get the current timestamp in seconds from RTC. The current timestamp n seconds which is calculated from 1970.1.1 00:00:00 (YEAR.MONTH.DAY, OUR: MIN: SECONDS).

Syntax

int32_t RTC::Read(void);

Parameters

The function requires no input parameter.

Returns

The function returns the current timestamp in seconds which is alculated from 1970.1.1 00:00:00 (YEAR.MONTH.DAY, HOUR: MIN: ECONDS).

Example Code

Example: RTC

Details of the code can be found in the previous section of RTC::Init .

Notes and Warnings NA

RTC:: Wait

Description

Send IR raw data.

Syntax

void RTC::wait(float s);

Parameters

s : unit microseconds (1 us)

Returns

The function returns nothing.

Example Code

Example: RTC

Details of the code can be found in the previous section of RTC::Init.

Notes and Warnings

NA

RTC:: SetEpoch

Description

Convert human-readable time to epoch time

Syntax

int RTC:: SetEpoch(int year, int month, int day, int hour, int min, int sec);

Parameters

year : user input year

month : user input month

day : user input day

hour : user input hour

min : user input minutes

sec : user input seconds

Returns

The function returns epoch time in seconds for RTC use.

Example Code

Example: RTC

Details of the code can be found in the previous section of RTC::Init.

Notes and Warnings

NA