Mikroelektronika d.o.o.
SKU: MIKROE-5426RTC 19 Click Board
RTC 19 Click Board
Couldn't load pickup availability
Key Features
- Low power consumption, automatic backup supply switch, integrated power switch, high accuracy, clock/calendar feature, programmable interrupt and clock output, automatic leap year recognition, and more
- Based on the MAX31334 - real-time clock from Analog Devices
- Can be used for general-consumer applications, including daily alarms, metering applications, and others requiring an accurate RTC for their operation
- mikroBUS: I2C Interface
The RTC 19 Click Board™ is a compact add-on board that measures the passing of time. This board features the MAX31334, an I2C-configurable real-time clock with an integrated power switch from Analog Devices. The MAX31334 provides information like seconds, minutes, hours, days, months, years, and dates based on a 32.768kHz quartz crystal through an I2C serial interface to transmit time and calendar data to the MCU. It also has an alarm function that outputs an interrupt signal to the MCU when the day of the week, hour, or minute matches with the pre-set time, as well as a programmable square-wave output, event detection input with timestamping, and backup supply. This Click board™ is suitable for general-consumer applications, including daily alarms, metering applications, and others requiring an accurate RTC for their operation.
The RTC 19 Click Board™ is supported by a mikroSDK-compliant library, which includes functions that simplify software development. This Click board™ comes as a thoroughly tested product, ready to be used on a system equipped with the mikroBUS™ socket.
How Does The RTC 19 Click Board™ Work?
The RTC 19 Click Board™ is based on the MAX31334, an ultra-low power, real-time clock (RTC) time-keeping device from Analog Devices. The MAX31334 is configured to transmit calendar and time data to the MCU (24-hour/12-hour format) based on a 32.768kHz quartz crystal and comes with an integrated interrupt generation function. It reads and writes clock/calendar data from and to the MCU in units ranging from seconds to the last two digits of the calendar year, providing seconds, minutes, hours, days, months, year, and date information. The end-of-the-month date is automatically adjusted for months with fewer than 31 days, including corrections for the leap year.
The MAX31334 features an integrated high-side power pass switch (detectable through a PSW pin and drawn to the TP1 testpoint for external use), enabling idle, ultra-low power modes on duty-cycled applications by disconnecting power to other devices on the system. The power switch ON/OFF durations can be controlled by periodic interrupt sources such as a countdown timer (programmable from 100ms to 1hr), alarms (1s resolution), or by an external interrupt from a DIN pushbutton.
The DIN signal represents a digital Schmitt trigger that records timestamps or asserts an interrupt on its falling/rising edge. In addition to the DIN button, the state of this signal can also be changed digitally using the DIN pin, routed on the RST pin of the mikroBUS™ socket. The selection can be performed using an onboard SMD jumper labelled DIN SEL, placing it in an appropriate position marked as MB or T, where MB stands for mikroBUS and T for the button.
The RTC 19 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. It also incorporates an alarm circuitry configured to generate a time-of-day/date interrupt signal. An alarm (interrupt) signal, marked as INA and routed to the INT pin of the mikroBUS™ socket, allows outputting warning every day or on a specific day visually indicated by a red LED marked as ALARM.
By utilizing an automatic backup switch, when the main supply drops below the programmed threshold voltage, this RTC can use an external power source (220mF supercapacitor), allowing uninterrupted operation. Besides an automatic backup switchover circuit, this board also carries a header for additional alarm/interrupt and a programmable clock output signal for frequencies from 1Hz to 32kHz available on an onboard J1 header. In addition, this signal also exists on the AN pin of the mikroBUS™ socket marked with INTB.
The RTC 19 Click Board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the 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.
SPECIFICATIONS
| Type | RTC |
| Applications | It can be used for general-consumer applications, including daily alarms, metering applications, and others requiring an accurate RTC for their operation |
| On-board modules | MAX31334 - real-time clock from Analog Devices |
| Key Features | Low power consumption, automatic backup supply switch, integrated power switch, high accuracy, clock/calendar feature, programmable interrupt and clock output, automatic leap year recognition, and more |
| Interface | I2C |
| Compatibility | mikroBUS |
| Click board size | M (42.9 x 25.4 mm) |
| Input Voltage | 3.3V or 5V |
PINOUT DIAGRAM
This table shows how the pinout of the RTC 19 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
| Notes | Pin |  |
Pin | Notes | |||
|---|---|---|---|---|---|---|---|
| Clock/Alarm Interrupt B | INB | 1 | AN | PWM | 16 | PSW | Power Switch |
| Schmitt Trigger | DIN | 2 | RST | INT | 15 | INA | Alarm Interrupt A |
| NC | 3 | CS | RX | 14 | NC | ||
| NC | 4 | SCK | TX | 13 | NC | ||
| NC | 5 | MISO | SCL | 12 | SCL | I2C Clock | |
| NC | 6 | MOSI | SDA | 11 | SDA | I2C Data | |
| Power Supply | 3.3V | 7 | 3.3V | 5V | 10 | 5V | Power Supply |
| Ground | GND | 8 | GND | GND | 9 | GND | Ground |
ONBOARD SETTINGS AND INDICATORS
| Label | Name | Default | Description |
|---|---|---|---|
| LD1 | PWR | - | Power LED Indicator |
| LD2 | ALARM | - | Alarm LED Indicator |
| JP1 | VCC SEL | Left | Logic Level Voltage Selection 3V3/5V: Left position 3V3, Right position 5V |
| JP2 | DIN SEL | Right | Schmitt Trigger Selection MB/T: Left position MB, Right position T |
| J1 | J1 | Unpopulated | Programmable Clock/Interrupt Output Header |
| T1 | DIN | - | External Trigger Button |
RTC 19 CLICK ELECTRICAL SPECIFICATIONS
| Description | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage | 3.3 | - | 5 | V |
| Memory Size (RAM) | - | - | 32 | bytes |
| Clock Output | 1 | - | 32 | kHz |
Software Support
We provide a library for the RTC 19 Click Board™ and a demo application (example), developed using MikroE compilers. The demo can run on all the main MikroE development boards.
The package can be downloaded/installed directly from NECTO Studio The package Manager(recommended), downloaded from our LibStock™ or found on the MikroE Github account.
Library Description
This library contains API for the RTC 19 Click Board™ driver.
Key functions
-
rtc19_set_timeThis function sets the starting time values - second, minute and hour. -
rtc19_read_timeThis function reads the current time values - second, minute and hour. -
rtc19_read_dateThis function reads the current date values - day of week, day, month and year.
Example Description
This example demonstrates using the RTC 19 Click Board™ by reading and displaying the time and date values.
void application_task ( void )
{
// Wait for a timer countdown flag configured at 1 Hz
while ( rtc19_get_inta_pin ( &rtc19 ) );
Delay_ms ( 100 );
rtc19_clear_interrupts ( &rtc19 );
if ( RTC19_OK == rtc19_read_time ( &rtc19, &time ) )
{
log_printf( &logger, " Time: %.2u:%.2u:%.2urn",
( uint16_t ) time.hour, ( uint16_t ) time.minute, ( uint16_t ) time.second );
}
if ( RTC19_OK == rtc19_read_date ( &rtc19, &date ) )
{
log_printf( &logger, " Date: %s, %.2u.%.2u.20%.2u.rn",
rtc19_get_day_of_week_name ( date.day_of_week ),
( uint16_t ) date.day, ( uint16_t ) date.month, ( uint16_t ) date.year );
}
}
The complete application code and ready-to-use projects can be installed directly from NECTO Studio The package Manager(recommended) is downloaded from our LibStock™ or found on the MikroE Github account.
Other MikroE Libraries used in the example:
- MikroSDK.Board
- MikroSDK.Log
- Click.RTC19
Additional Notes and Information
Depending on the development board you are using, you may need USB UART Click Board™, USB UART 2 Click or RS232 Click to connect to your PC for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroE compilers.
MIKROSDK
The RTC 19 Click Board™ is supported with mikroSDK - MikroE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.
RTC 19 Click Board
Frequently Asked Questions
Have a Question?
Be the first to ask a question about this.