Beginner
10 min

Master time management with DS1307 and STM32F746ZG

Keep track of time in various electronic applications

RTC 2 Click with UNI-DS v8

Published Oct 20, 2023

Click board™

RTC 2 Click

Dev. board

UNI-DS v8

Compiler

NECTO Studio

MCU

STM32F746ZG

Compact time-tracking solution that maintains accurate time records, suitable for applications like IoT, wearables, data logging, and industrial devices

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Hardware Overview

How does it work?

RTC 2 Click is based on the DS1307, a 64x8 serial I2C Real-Time clock from Analog Devices. It is a low-power, full binary-coded decimal (BCD) clock/calendar with 56 bytes of NV SRAM. The end of months is automatically adjusted for months with fewer than 31 days, including corrections for the leap year. The clock can operate in either a 24-hour or 12-hour format with an AM/PM indicator. The RTC has a built-in power-sense circuit that automatically switches to the backup power

supply when it detects a power failure. The RTC 2 comes equipped with a 3V/230mA lithium battery, ensuring timekeeping continues even when the main power supply goes OFF. The RTC 2 Click uses an I2C 2-Wire interface for communication with the host MCU, with a clock rate of up to 400kHz. The interrupt INT pin of this Click board™ outputs one of four square-wave frequencies (1Hz, 4kHz, 8kHz, and 32kHz). When enabled, it outputs frequency depending on values set in configuration

bits. This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

RTC 2 Click hardware overview image

Features overview

Development board

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M7

MCU Memory (KB)

1024

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

327680

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PD3
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB8
SCL
I2C Data
PB9
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RTC 2 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
Board mapper by product7 hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for RTC 2 Click driver.

Key functions:

  • rtc2_read_byte - Generic read byte of data function

  • rtc2_write_byte - Generic write byte of data function

  • rtc2_enable_counting - Enable counting function

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 
 * \brief Rtc6 Click example
 * 
 * # Description
 * This application enables usage of Real-TIme clock and calendar with alarm on RTC 6 Click.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver init, sets time zone, sets UTC-GMT time and alarm time
 * 
 * ## Application Task  
 * Reads GMT time and Local time. Checks if the alarm is activated. 
 * If the alarm is active, it disable alarm and adjusts the new one within 20 seconds.
 * Logs this data on USBUART every 900ms.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rtc6.h"

// ------------------------------------------------------------------ VARIABLES

static rtc6_t rtc6;
static log_t logger;
static rtc6_time_t utc_time;
static rtc6_time_t alarm_time;
static rtc6_time_t local_time;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    rtc6_cfg_t cfg;
    int8_t time_zone = 2;

    /** 
     * 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.

    rtc6_cfg_setup( &cfg );
    RTC6_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rtc6_init( &rtc6, &cfg );

    // Set UTC time

    utc_time.seconds  = 40;
    utc_time.minutes  = 59;
    utc_time.hours    = 23;
    utc_time.monthday = 14;
    utc_time.month    = 12;
    utc_time.year     = 18;
    
    // Set alarm time
    
    alarm_time.seconds  = 0;
    alarm_time.minutes  = 0;
    alarm_time.hours    = 0;
    alarm_time.weekdays  = 0;
    alarm_time.monthday = 15;
    alarm_time.month    = 12;
    alarm_time.year     = 18;

    rtc6_default_cfg( &rtc6, time_zone, &utc_time, &alarm_time );
    log_info( &logger, " ----- Init successfully ----- " );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

void application_task ( void )
{
    //  Task implementation.

    rtc6_get_gmt_time( &rtc6, &utc_time );
    rtc6_get_local_time( &rtc6, &local_time );
    
    log_printf( &logger, "--- UTC time ---\r\nTime : %u %u %u\r\n", ( uint16_t )utc_time.hours, ( uint16_t )utc_time.minutes, ( uint16_t )utc_time.seconds );
    
    log_printf( &logger, "Date : %u %u %u\r\n", ( uint16_t )utc_time.monthday, ( uint16_t )utc_time.month, utc_time.year );
    
    log_printf( &logger, "--- Local time ---\r\nTime : %u %u %u\r\n", ( uint16_t )local_time.hours, ( uint16_t )local_time.minutes, ( uint16_t )local_time.seconds );

    log_printf( &logger, "Date : %u %u %u\r\n \r\n", ( uint16_t )local_time.monthday, ( uint16_t )local_time.month, local_time.year );
    
    if ( rtc6_is_active_alarm( &rtc6 ) != 0 )
    {
        log_printf( &logger, " ----- Active alarm ----- \r\n" );
        rtc6_disable_alarm( &rtc6, RTC6_ALARM_0 );
        rtc6_repeat_alarm( &rtc6, RTC6_ALARM_0, 20 );
    }

    Delay_ms ( 900 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}


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

Additional Support

Resources

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