Integrate real-time clock into your system for accurate timestamping and precise event sequencing
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Hardware Overview
How does it work?
RTC 16 Click is based on the BU9873, an I2C configurable real-time clock/calendar optimized for low-power operations from Rohm Semiconductors. The BU9873 is configured to perform the serial transmission of calendar and time data to the MCU and comes with an integrated interrupt generation function. It also contains a built-in high-precision oscillation adjustment circuit, which enables the adjustment of time counts with a digital method and correct deviations in the oscillation frequency of the crystal oscillator. An automatic leap year recognition also characterizes this RTC until the future 2099 year. 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. An alarm and interrupt function is also available that outputs an interrupt signal to the INT pin of the mikroBUS™ socket when the day of the week, hour, or minute matches with the preset time. An alarm may be selectable between ON and OFF for each day of the week, allowing outputting warning every day or on a specific day indicated by a red LED marked as ALARM. Besides, the RTC 16 Click also has an onboard header labeled CLKOUT, which provides clock pulses of 32kHz. Like this one, the most common RTC configuration is a
battery-backed-up, which maintains time and continues its work without interruption in the event of a power failure. That’s why, besides the BU9873, the RTC 16 Click has a button cell battery holder compatible with the 3000TR battery holder, suitable for 12mm Coin Cell batteries. 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. 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.
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.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC32
MCU Memory (KB)
2048
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
524288
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Track your results in real time
Application Output via Debug Mode
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.
Software Support
Library Description
This library contains API for RTC 16 Click driver.
Key functions:
rtc16_set_time
- This function sets the starting time values - second, minute and hourrtc16_read_time
- This function reads the current time values - second, minute and hourrtc16_read_date
- This function reads the current date values - day of week, day, month and year
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 RTC16 Click example
*
* # Description
* This example demonstrates the use of RTC 16 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 performs the click default configuration
* which sets 24h time mode and interrupt to be synchronized with second count-up.
* And after that setting the starting time and date.
*
* ## Application Task
* Waits for the second count-up interrupt and then reads and displays the current
* time and date values on the USB UART.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "rtc16.h"
static rtc16_t rtc16;
static log_t logger;
static rtc16_time_t time;
static rtc16_date_t date;
/**
* @brief RTC 16 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 #rtc16_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 *rtc16_get_day_of_week_name ( uint8_t day_of_week );
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
rtc16_cfg_t rtc16_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.
rtc16_cfg_setup( &rtc16_cfg );
RTC16_MAP_MIKROBUS( rtc16_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == rtc16_init( &rtc16, &rtc16_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( RTC16_ERROR == rtc16_default_cfg ( &rtc16 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
time.hour = 23;
time.minute = 59;
time.second = 50;
if ( RTC16_OK == rtc16_set_time ( &rtc16, &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 = RTC16_SUNDAY;
date.day = 31;
date.month = 12;
date.year = 22;
if ( RTC16_OK == rtc16_set_date ( &rtc16, &date ) )
{
log_printf( &logger, " Set date: %s, %.2u.%.2u.20%.2u.\r\n",
rtc16_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 )
{
// Wait for interrupt which is synchronized with second count-up
while ( rtc16_get_int_pin ( &rtc16 ) );
rtc16_clear_interrupts ( &rtc16 );
if ( RTC16_OK == rtc16_read_time ( &rtc16, &time ) )
{
log_printf( &logger, " Time: %.2u:%.2u:%.2u\r\n",
( uint16_t ) time.hour, ( uint16_t ) time.minute, ( uint16_t ) time.second );
}
if ( RTC16_OK == rtc16_read_date ( &rtc16, &date ) )
{
log_printf( &logger, " Date: %s, %.2u.%.2u.20%.2u.\r\n\n",
rtc16_get_day_of_week_name ( date.day_of_week ),
( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
static char *rtc16_get_day_of_week_name ( uint8_t day_of_week )
{
switch ( day_of_week )
{
case RTC16_MONDAY:
{
return "Monday";
}
case RTC16_TUESDAY:
{
return "Tuesday";
}
case RTC16_WEDNESDAY:
{
return "Wednesday";
}
case RTC16_THURSDAY:
{
return "Thursday";
}
case RTC16_FRIDAY:
{
return "Friday";
}
case RTC16_SATURDAY:
{
return "Saturday";
}
case RTC16_SUNDAY:
{
return "Sunday";
}
default:
{
return "Unknown";
}
}
}
// ------------------------------------------------------------------------ END