Incorporate a high-performance real-time clock into your solution and boost your timing control
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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.
Features overview
Development board
Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All
these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware
quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.
Microcontroller Overview
MCU Card / MCU

Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3615
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project 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 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 Clickrtc3_get_time
- Function gets time: hours, minutes and seconds data from the target register address of PCF8583 chip on RTC 3 Clickrtc3_set_calibration
- Function set calibration by write CAL_CFG1 register of BQ32000 chip
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 Rtc3 Click example
*
* # Description
* This example demonstrates the use of RTC 3 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 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 ( 1 == day_of_the_week )
{
log_printf( &logger, " Monday \r\n" );
}
if ( 2 == day_of_the_week )
{
log_printf( &logger, " Tuesday \r\n" );
}
if ( 3 == day_of_the_week )
{
log_printf( &logger, " Wednesday \r\n" );
}
if ( 4 == day_of_the_week )
{
log_printf( &logger, " Thursday \r\n" );
}
if ( 5 == day_of_the_week )
{
log_printf( &logger, " Friday \r\n" );
}
if ( 6 == day_of_the_week )
{
log_printf( &logger, " Saturday \r\n" );
}
if ( 7 == day_of_the_week )
{
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 );
Delay_ms ( 100 );
// Stop counting
rtc3_set_counting( &rtc3, 0 );
// 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: 6 ( Day of the week ), 31 ( day ), 12 ( month ) and 2022 ( year )
rtc3.date.day_of_the_week = 6;
rtc3.date.date_day = 31;
rtc3.date.date_month = 12;
rtc3.date.date_year = 22;
rtc3_set_date( &rtc3 );
// Start counting
rtc3_set_counting( &rtc3, 1 );
Delay_ms ( 100 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
static uint8_t time_seconds = 0xFF;
rtc3_get_time( &rtc3 );
rtc3_get_date( &rtc3 );
if ( time_seconds != rtc3.time.time_seconds )
{
display_log_day_of_the_week ( rtc3.date.day_of_the_week );
log_printf( &logger, " Time: %.2u:%.2u:%.2u\r\n Date: %.2u.%.2u.20%.2u.\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 = rtc3.time.time_seconds;
}
Delay_ms ( 200 );
}
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