Beginner
10 min

Seize every moment with BQ32000 and PIC18F57Q43

Timekeeping excellence

RTC 3 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

RTC 3 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Incorporate a high-performance real-time clock into your solution and boost your timing control

A

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Hardware Overview

How does it work?

RTC 3 Click is based on the BQ32000, a real-time clock from Texas Instruments presenting a compatible replacement for industry standard real-time clocks. The BQ32000 features an automatic backup supply with an integrated trickle charger for an automatic switchover to a backup power supply providing additional reliability (the circuit maintains the backup charge with an onboard supercapacitor). It also comes with a programmable calibration adjustment from –63ppm to +126ppm and clock frequency derived from an onboard 32.768KHz oscillator. The BQ32000 communicates with the MCU using the standard I2C 2-Wire interface with a maximum

frequency of 400kHz. Its time registers are updated once per second, with registers updated simultaneously to prevent a time-keeping glitch. It should be noted that when the BQ32000 switches from the main power supply to the backup supply, the time-keeping register cannot be accessed via the I2C interface. The access to these registers is only with supply voltage present. The time-keeping registers can take up to one second to update after the device switches from the backup power supply to the main power supply. The BQ32000 also includes an automatic leap year correction and general interrupt or oscillator fail flag indicating the status of the RTC oscillator

routed to the INT pin of the mikroBUS™ socket. The RTC classifies a leap year as any year evenly divisible by 4. Using this rule allows for reliable leap-year compensation until 2100. The host MCU must compensate for years that fall outside this rule. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

RTC 3 Click hardware overview 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
NC
NC
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
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

RTC 3 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

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for RTC 3 Click driver.

Key functions:

  • rtc3_set_time - Function sets time: hours, minutes and seconds data to the target register address of PCF8583 chip on RTC 3 Click

  • rtc3_get_time - Function gets time: hours, minutes and seconds data from the target register address of PCF8583 chip on RTC 3 Click

  • rtc3_set_calibration - Function set calibration by write CAL_CFG1 register of BQ32000 chip

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 
 * \brief Rtc3 Click example
 * 
 * # Description
 * This application enables time measurment over RTC3 click.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization driver enable's - I2C,
 * set start time and date, enable counting and start write log.
 * 
 * ## Application Task  
 * This is a example which demonstrates the use of RTC 3 Click board.
 * RTC 3 Click communicates with register via I2C by write to register and read from register,
 * set time and date, get time and date, enable and disable counting
 * and set frequency by write configuration register.
 * Results are being sent to the Usart Terminal where you can track their changes.
 * All data logs write on usb uart changes for every 1 sec.
 * 
 * *note:* 
 * Time stats measuring correctly but from 0 seconds, after 10 seconds.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rtc3.h"

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

static rtc3_t rtc3;
static log_t logger;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

void display_log_day_of_the_week ( uint8_t day_of_the_week )
{
    if ( day_of_the_week == 1 )
    {
        log_printf( &logger, "      Monday      \r\n" );
    }        
    if ( day_of_the_week == 2 )
    {
        log_printf( &logger, "      Tuesday     \r\n" );
    }        
    if ( day_of_the_week == 3 )
    {
        log_printf( &logger, "     Wednesday    \r\n" );
    }        
    if ( day_of_the_week == 4 )
    {
        log_printf( &logger, "     Thursday     \r\n" );
    }        
    if ( day_of_the_week == 5 )
    {
        log_printf( &logger, "      Friday      \r\n" );
    }        
    if ( day_of_the_week == 6 )
    {
        log_printf( &logger, "     Saturday     \r\n" );
    }
    if ( day_of_the_week == 7 )
    {
        log_printf( &logger, "      Sunday      \r\n" );
    }
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rtc3_cfg_t cfg;

    /** 
     * 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.

    rtc3_cfg_setup( &cfg );
    RTC3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rtc3_init( &rtc3, &cfg );

    /// Set Time: 23h, 59 min, 50 sec

    rtc3.time.time_hours = 23;
    rtc3.time.time_minutes = 59;
    rtc3.time.time_seconds = 50;

    rtc3_set_time( &rtc3 );

    // Set Date: 1 ( Day of the week ), 31 ( day ), 12 ( month ) and 2018 ( year )

    rtc3.date.day_of_the_week = 1;
    rtc3.date.date_day = 31;
    rtc3.date.date_month = 12;
    rtc3.date.date_year = 2018;

    rtc3_set_date( &rtc3 );

    // Start counting
   
    rtc3_enable_disable_counting( &rtc3, 1 );
    Delay_100ms( );
    
    Delay_ms( 1000 );
}

void application_task ( void )
{
    //  Task implementation.

    uint8_t time_seconds_new = 0xFF;
    
     

    rtc3_get_time( &rtc3 );

    rtc3_get_date( &rtc3 );

    if ( time_seconds_new != rtc3.time.time_seconds )
    {
        if ( ( ( rtc3.time.time_hours | rtc3.time.time_minutes | rtc3.time.time_seconds ) == 0 )  && ( ( rtc3.date.date_day | rtc3.date.date_month ) == 1 ) )
        {
            log_printf( &logger, "  Happy New Year  \r\n" );
            log_printf( &logger, "------------------\r\n" );
        }

        log_printf( &logger, " Time : %d:%d:%d \r\n Date: %d.%d.20%d.\r\n------------------\r\n", (uint16_t)rtc3.time.time_hours, (uint16_t)rtc3.time.time_minutes,
                                                                                            (uint16_t)rtc3.time.time_seconds, 
                                                                                            (uint16_t)rtc3.date.date_day, (uint16_t)rtc3.date.date_month, (uint16_t)rtc3.date.date_year );

        time_seconds_new = rtc3.time.time_seconds;
    }

    Delay_ms( 200 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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