Intermediate
30 min

Get the perfect timing you need with RV-3032-C7 and PIC18F57Q43

Tick-tock, tick-tock!

RTC 18 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

RTC 18 Click

Dev.Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Say goodbye to time inaccuracies with RV-3032-C7 - the real-time clock that keeps you on schedule

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Hardware Overview

How does it work?

RTC 18 Click is based on the RV-3032-C7, a highly accurate real-time clock/calendar module optimized for low-power operations from Micro Crystal AG. The RV-3032-C7 has a built-in 32.768kHz “Tuning Fork” crystal oscillator and HF oscillator and counters for hundredths of seconds, seconds, minutes, hours, dates, months, years, and weekdays. Its temperature compensation circuitry is factory calibrated, resulting in the highest time accuracy of ±2.5ppm over the entire temperature range, with additional non-volatile aging offset correction. This RTC also comes with an integrated digital thermometer for actual internal temperature measurement in °C with a typical accuracy of ±1°C, resolution of 0.0625°C/step, and a programmable alarm on top and bottom temperature limits. Alongside all these features, it also supports an automatic leap year correction. The calendar year will

automatically be identified as a leap year when its last two digits are a multiple of 4. Consequently, leap years up to the year 2099 can automatically be recognized. 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 an alarm circuitry configured to generate an interrupt signal for Periodic Countdown Timer and Periodic Time Update (seconds, minutes), date/hour/minute alarm, and an external event registered with the CS pin on the mikroBUS™ socket. An alarm (interrupt) signal routed to the INT pin of the mikroBUS™ socket allows outputting warning every day or on a specific day visually indicated by a red LED marked as ALARM. The RV-3032-C7 also includes an automatic backup switchover circuit allowing it to be used with a single-button cell battery

for an extended period. This feature can be activated by positioning SMD jumpers labeled as BATT SEL in an appropriate position marked as OFF or ON. Besides an automatic backup switchover circuit, it has a trickle charger with a charge pump providing full RTC functions with programmable counters, alarm, selectable interrupt, and programmable clock output functions for frequencies from 1Hz to 52MHz available on an onboard header labeled CLKO. 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. However, the 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 18 Click top side image
RTC 18 Click lateral side image
RTC 18 Click bottom side image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
External Event Interrupt
PD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PA6
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB1
SCL
I2C Data
PB2
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

RTC 18 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Barometer 13 Click front image hardware assembly
PIC18F57Q43 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Curiosity Nano with PICXXX 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
PIC18F57Q43 Curiosity 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

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for RTC 18 Click driver.

Key functions:

  • rtc18_read_time This function reads the current time values - second, minute, and hour.

  • rtc18_read_date This function reads the current date values - day of week, day, month, and year.

  • rtc18_read_temperature This function reads temperature measurements in Celsius.

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @file main.c
 * @brief RTC18 Click example
 *
 * # Description
 * This example demonstrates the use of RTC 18 click board by reading and displaying
 * the time and date values as well as the temperature measurements in Celsius.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger and performs the click default configuration
 * which enables the periodic interrupt on seconds count-up, and sets the starting time and date.
 *
 * ## Application Task
 * Waits for the second count-up interrupt and then reads and displays on the USB UART 
 * the current time and date values as well as the temperature measurements in Celsius.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "rtc18.h"

static rtc18_t rtc18;
static log_t logger;
static rtc18_time_t time;
static rtc18_date_t date;

/**
 * @brief RTC 18 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 #rtc18_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 char *rtc18_get_day_of_week_name ( uint8_t day_of_week );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rtc18_cfg_t rtc18_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.
    rtc18_cfg_setup( &rtc18_cfg );
    RTC18_MAP_MIKROBUS( rtc18_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == rtc18_init( &rtc18, &rtc18_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( RTC18_ERROR == rtc18_default_cfg ( &rtc18 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    time.hour = 23;
    time.minute = 59;
    time.second = 50;
    if ( RTC18_OK == rtc18_set_time ( &rtc18, &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 = RTC18_SATURDAY;
    date.day = 31;
    date.month = 12;
    date.year = 22;
    if ( RTC18_OK == rtc18_set_date ( &rtc18, &date ) )
    {
        log_printf( &logger, " Set date: %s, %.2u.%.2u.20%.2u.\r\n", 
                    rtc18_get_day_of_week_name ( date.day_of_week ),
                    ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float temperature;
    
    // Wait for a second count-up interrupt
    while ( rtc18_get_int_pin ( &rtc18 ) );
    
    Delay_ms ( 10 );
    rtc18_clear_periodic_interrupt ( &rtc18 );
    
    if ( RTC18_OK == rtc18_read_time ( &rtc18, &time ) )
    {
        log_printf( &logger, " Time: %.2u:%.2u:%.2u\r\n", 
                    ( uint16_t ) time.hour, ( uint16_t ) time.minute, ( uint16_t ) time.second );
    }
    if ( RTC18_OK == rtc18_read_date ( &rtc18, &date ) )
    {
        log_printf( &logger, " Date: %s, %.2u.%.2u.20%.2u.\r\n", 
                    rtc18_get_day_of_week_name ( date.day_of_week ),
                    ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
    }
    if ( RTC18_OK == rtc18_read_temperature ( &rtc18, &temperature ) )
    {
        log_printf( &logger, " Temperature: %.2f C\r\n\n", temperature );
    }
}

void main ( void ) 
{
    application_init( );

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

static char *rtc18_get_day_of_week_name ( uint8_t day_of_week )
{
    switch ( day_of_week )
    {
        case RTC18_MONDAY:
        {
            return "Monday";
        }
        case RTC18_TUESDAY:
        {
            return "Tuesday";
        }
        case RTC18_WEDNESDAY:
        {
            return "Wednesday";
        }
        case RTC18_THURSDAY:
        {
            return "Thursday";
        }
        case RTC18_FRIDAY:
        {
            return "Friday";
        }
        case RTC18_SATURDAY:
        {
            return "Saturday";
        }
        case RTC18_SUNDAY:
        {
            return "Sunday";
        }
        default:
        {
            return "Unknown";
        }
    }
}

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

Additional Support

Resources