Intermediate
30 min

Experience RTC excellence today with PT7C4311 and STM32F031K6

Timing is everything: Elevate your projects with our RTC solution

RTC 21 Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

RTC 21 Click

Dev Board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Integrate efficient real-time clock into your solution for precise event timing and seamless synchronization

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Hardware Overview

How does it work?

RTC 21 Click is based on the PT7C4311, an ultra-low power, real-time clock (RTC) time-keeping device from Diodes Incorporated. The PT7C4311 is configured to transmit calendar and time data to the MCU (24-hour format) based on a 32.768kHz quartz crystal and comes with 56 bytes of general-purpose RAM. It reads and writes clock/calendar data from and to the MCU in units ranging from seconds to the last two digits of the calendar year, providing seconds, minutes, hours, dates, days, months, year, and century information.

The end-of-the-month date is automatically adjusted for months with fewer than 31 days, including corrections for the leap year until 2100. This Click board™ communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Fast Mode operation up to 400kHz. It also incorporates one open-drain output labeled FT, which can be used as a frequency test signal (512Hz square-wave password for frequency test purposes) or as a register-configurable output DC level when

square-wave is disabled. The PT7C4311 also includes an automatic backup switchover circuit, allowing it to be used with a single-button cell battery for an extended period. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used for further development.

RTC 21 Click top side image
RTC 21 Click bottom side image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Frequency Test/DC Level
PA12
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RTC 21 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
2x4 RGB Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-32 with STM32 MCU MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

This Click board can be interfaced and monitored in two ways:

  • Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.

Software Support

Library Description

This library contains API for RTC 21 Click driver.

Key functions:

  • rtc21_set_time - This function sets the starting time values - second, minute and hour

  • rtc21_set_date - This function sets the starting date values - day of week, day, month and year

  • rtc21_read_time - This function reads the current time values - second, minute and hour

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * @file main.c
 * @brief RTC 21 Click example
 *
 * # Description
 * This example demonstrates the use of RTC 21 click board by reading and displaying
 * the time and date values.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger and then sets the starting time and date.
 *
 * ## Application Task
 * Reads and displays on the USB UART the current time and date values once per second.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "rtc21.h"

static rtc21_t rtc21;
static log_t logger;
static rtc21_time_t time;
static rtc21_date_t date;

/**
 * @brief RTC 21 get day of week name function.
 * @details This function returns the name of day of the week as a string.
 * @param[in] ctx : Click context object.
 * See #rtc21_t object definition for detailed explanation.
 * @param[in] day_of_week : Day of week decimal value.
 * @return Name of day as a string.
 * @note None.
 */
static uint8_t *rtc21_get_day_of_week_name ( uint8_t day_of_week );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rtc21_cfg_t rtc21_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    rtc21_cfg_setup( &rtc21_cfg );
    RTC21_MAP_MIKROBUS( rtc21_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == rtc21_init( &rtc21, &rtc21_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    time.hour = 23;
    time.minute = 59;
    time.second = 50;
    if ( RTC21_OK == rtc21_set_time ( &rtc21, &time ) )
    {
        log_printf( &logger, " Set time: %.2u:%.2u:%.2u\r\n", 
                    ( uint16_t ) time.hour, ( uint16_t ) time.minute, ( uint16_t ) time.second );
    }
    date.day_of_week = RTC21_SATURDAY;
    date.day = 31;
    date.month = 12;
    date.year = 22;
    if ( RTC21_OK == rtc21_set_date ( &rtc21, &date ) )
    {
        log_printf( &logger, " Set date: %s, %.2u.%.2u.20%.2u.\r\n", 
                    rtc21_get_day_of_week_name ( date.day_of_week ),
                    ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
    }
    Delay_ms ( 100 );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    if ( RTC21_OK == rtc21_read_time ( &rtc21, &time ) )
    {
        log_printf( &logger, " Time: %.2u:%.2u:%.2u\r\n", 
                    ( uint16_t ) time.hour, ( uint16_t ) time.minute, ( uint16_t ) time.second );
    }
    if ( RTC21_OK == rtc21_read_date ( &rtc21, &date ) )
    {
        log_printf( &logger, " Date: %s, %.2u.%.2u.20%.2u.\r\n", 
                    rtc21_get_day_of_week_name ( date.day_of_week ),
                    ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
    }
    Delay_ms ( 1000 );
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

static uint8_t *rtc21_get_day_of_week_name ( uint8_t day_of_week )
{
    switch ( day_of_week )
    {
        case RTC21_MONDAY:
        {
            return "Monday";
        }
        case RTC21_TUESDAY:
        {
            return "Tuesday";
        }
        case RTC21_WEDNESDAY:
        {
            return "Wednesday";
        }
        case RTC21_THURSDAY:
        {
            return "Thursday";
        }
        case RTC21_FRIDAY:
        {
            return "Friday";
        }
        case RTC21_SATURDAY:
        {
            return "Saturday";
        }
        case RTC21_SUNDAY:
        {
            return "Sunday";
        }
        default:
        {
            return "Unknown";
        }
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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