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
EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more
efficiently than ever. Each part of the EasyAVR v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B)
connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets which cover a wide range of 16-bit AVR MCUs. EasyAVR v7 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
![ATmega1284](https://dbp-cdn.mikroe.com/catalog/mcus/resources/ATmega1284.jpg)
Architecture
AVR
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
16384
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
![RTC 3 Click Schematic schematic](https://dbp-cdn.mikroe.com/catalog/click-boards/resources/1ee790db-fa54-6a7a-aebf-0242ac120009/schematic.webp)
Step by step
Project assembly
Track your results in real time
Application Output
After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.
![UART Application Output Step 1](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703a-40a0-6b58-88de-02420a00029a/UART-AO-Step-1.jpg)
Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.
![UART Application Output Step 2](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703a-eb29-62fa-ba91-02420a00029a/UART-AO-Step-2.jpg)
In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".
![UART Application Output Step 3](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703b-7543-6fbc-9c69-0242ac120003/UART-AO-Step-3.jpg)
The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
![UART Application Output Step 4](https://dbp-cdn.mikroe.com/cms/shared-resources/1eed703c-068c-66a4-a4fc-0242ac120003/UART-AO-Step-4.jpg)
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
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