Intermediate
30 min

Always be on time with AB0815 and PIC32MZ2048EFM100

RTC: Your silent reminder in a noisy world

RTC 11 Click with Curiosity PIC32 MZ EF

Published Oct 20, 2023

Click board™

RTC 11 Click

Dev Board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Integrate reliable real-time clock into your solution to enable precise event sequencing and accurate time measurement

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Hardware Overview

How does it work?

RTC 11 Click is based on the AB0815, an ultra-low-power coupled with a highly sophisticated feature set, the real-time clock from Abracon. The AB0815 is a full-function RTC and includes three feature groups: baseline and advanced timekeeping features and power management. Functions from each feature group may be controlled via I/O offset mapped registers accessed through the SPI serial interface. The baseline timekeeping feature group supports the standard 32.786 kHz crystal oscillation mode for maximum frequency accuracy with an ultra-low current draw of 22nA. This feature includes standard counters for minutes, hours, dates, months, years, and weekdays. A complement of countdown timers and alarms may additionally be set to initiate interrupts or

resets on several outputs. The most common configuration on this Click board™ is a battery-backed-up RTC, which maintains time and may hold data in RAM. In addition to the AB0815, the RTC 11 Click is equipped with a button cell battery holder compatible with the 3000TR battery holder, suitable for 12mm Coin Cell batteries. By utilizing an automatic backup switch, the AB0815 can use an external battery power source when there is no power supply on its main power terminals, thus allowing for uninterrupted operation. The AB0815 communicates with MCU using the standard SPI serial interface that supports modes 0 and 3 with a maximum frequency of 2 MHz. The flexible inputs of the AB0815 can be used to aggregate various interrupt sources, including external digital inputs,

analog levels, timers, and alarms, into a single interrupt source to an MCU. Based on this, functions like external interrupt or watchdog timer reset could be found on this Click board™ routed on the RST and AN pins of the mikroBUS™ socket labeled as EXI and WDI, as well as the primary and secondary interrupt outputs routed on the INT and PWM pins of the mikroBUS™ socket labeled as IT1 and IT2. 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. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

RTC 11 Click top side image
RTC 11 Click bottom side image

Features overview

Development board

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Watchdog Timer Reset
RPB4
AN
External Interrupt
RA9
RST
SPI Chip Select
RPD4
CS
SPI Clock
RPD1
SCK
SPI Data OUT
RPD14
MISO
SPI Data IN
RPD3
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Secondary Interrupt
RPE8
PWM
Primary Interrupt
RF13
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RTC 11 Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
Curiosity PIC32 MZ EF MB 1 Access - 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
Curiosity PIC32 MZ EF 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 11 Click driver.

Key functions:

  • rtc11_set_time - Set time hours, minutes and seconds function

  • rtc11_get_time - Get time hours, minutes and seconds function

  • rtc11_set_date - Set date day of the week, day, month and year 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 main.c
 * @brief RTC11 Click example
 *
 * # Description
 * This is an example that demonstrates the use of the RTC 11 click board™.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initalizes SPI, performs software reset, sets 
 * system time and date, and starts clocking system.
 *
 * ## Application Task
 * Demonstrates use of RTC 11 click board by reading and
 * displaying time and date via USART terminal.
 * 
 * Additional Functions :
 * 
 * void disp_day_of_the_week ( uint8_t w_day ) - Writes the day of the week on 
 * USART terminal.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "rtc11.h"

static rtc11_t rtc11;
static log_t logger;

static rtc11_time_t time;
static rtc11_date_t date;

uint8_t sec_flag = 0xFF;

void disp_day_of_the_week ( uint8_t w_day ) {
    switch ( w_day )
    {
        case 0 :
        {
            log_printf( &logger, "Monday" );
            break;
        }
        case 1 :
        {
            log_printf( &logger, "Tuesday" );
            break;
        }
        case 2 :
        {
            log_printf( &logger, "Wednesday" );
            break;
        }
        case 3 :
        {
            log_printf( &logger, "Thursday" );
            break;
        }
        case 4 :
        {
            log_printf( &logger, "Friday" );
            break;
        }
        case 5 :
        {
            log_printf( &logger, "Saturday" );
            break;
        }
        case 6 :
        {
            log_printf( &logger, "Sunday" );
            break;
        }
        default :
        {
        break;
        }
    }
}
void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    rtc11_cfg_t rtc11_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.

    rtc11_cfg_setup( &rtc11_cfg );
    RTC11_MAP_MIKROBUS( rtc11_cfg, MIKROBUS_1 );
    err_t init_flag  = rtc11_init( &rtc11, &rtc11_cfg );
    if ( SPI_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    log_printf( &logger,"------------------------\r\n" );
    log_printf( &logger," Software reset \r\n" );
    rtc11_soft_rst( &rtc11 );
    Delay_ms( 100 );
    
    time.hours = 23;
    time.min = 59;
    time.sec = 55;
    log_printf( &logger,"------------------------\r\n" );
    log_printf( &logger," Setting time: %.2d:%.2d:%.2d \r\n", ( uint16_t ) time.hours, ( uint16_t ) time.min, ( uint16_t ) time.sec );
    rtc11_set_time ( &rtc11, time );
    Delay_ms( 100 );
    
    date.day_of_week = 0;
    date.day = 19;
    date.month = 7;
    date.year = 21;
    log_printf( &logger,"------------------------\r\n" );
    log_printf( &logger," Setting date: %.2d/%.2d/%.2d \r\n", ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
    rtc11_set_date( &rtc11, date );
    Delay_ms( 100 );
    
    rtc11_stp_sys_slk ( &rtc11, RTC11_PROP_DIS );
    log_info( &logger, " Application Task " );
    log_printf( &logger,"------------------------\r\n" );
}

void application_task ( void ) {
    rtc11_get_time ( &rtc11, &time );
    Delay_ms( 10 );
    rtc11_get_date ( &rtc11, &date );
    Delay_ms( 10 );
    
    if ( sec_flag != time.sec ) {
        log_printf( &logger, " Date: " );
        disp_day_of_the_week( date.day_of_week );
        log_printf( &logger, " %.2d/%.2d/20%.2d \r\n", ( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
        log_printf( &logger, " Time: %.2d:%.2d:%.2d \r\n", ( uint16_t ) time.hours, ( uint16_t ) time.min, ( uint16_t ) time.sec );
        log_printf( &logger,"--------------------------\r\n" );
    }
    sec_flag = time.sec;
}

void main ( void ) {
    application_init( );

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

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

Additional Support

Resources

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