RTC 13 Click Board™

Product Code: MIKROE-4794

How Does The RTC 13 Click Board™ Work? The RTC 13 Click Board™ as its foundation uses the PCF2123, an SPI configurable real-time clock/calendar optimized for low power operations from NXP Semiconductors. It contains sixteen 8-bit registers with an auto-incrementing address counter, an on-chip 32.768kHz oscillator with two integrated load capacitors, a frequency divider that provides the source clock for the RTC, and a programmable clock output. The integrated oscillator ensures year, month, day, weekday, hours, minutes, and seconds, making this Click board™ suitable for various time-keeping applications such as high-duration timers, daily alarms, and many more. The PCF2123 communicates with MCU using the standard SPI serial interface with a maximum frequency of 8MHz, where data transfers serially with a maximum data rate of 6.25 Mbit/s. An alarm and timer function is also available, providing the possibility to generate a wake-up signal on an interrupt line, available on the INT pin of the mikroBUS™ socket, and indicated by a red LED marked as INT.

Besides, the RTC 13 Click Board™ also has an onboard header labeled CLKOUT, which provides a programmable square-wave output clock signal controlled by one GPIO pin, a CLE pin routed to the RTS pin the mikroBUS™ socket. Frequencies of 32.768kHz, representing a default value down to 1Hz, can be generated and used as a system and MCU clock, input to a charge pump, or calibration of the oscillator. The most common RTC configuration, like this one, is a battery-backed up, which maintains time and continues its work without interruption in the event of a power failure. That's why, in addition to the PCF2123, the RTC 13 Click is equipped with a button cell battery holder compatible with the 3000TR battery holder, suitable for 12mm Coin Cell batteries. The RTC 13 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 SPI 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 Can be used for various time-keeping applications, including high-duration timers, metering, daily alarms, low standby power applications, and many more On-board modules PCF2123 - SPI configurable real-time clock/calendar optimized for low power operations from NXP Semiconductors Key Features Low power consumption, clock/calendar feature, freely programmable timer and alarm with interrupt capability, battery back-up, programmable square wave clock output, and more Interface SPI 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 on the RTC 13 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes Pin Pin Notes NC 1 AN PWM 16 NC Clock Output Enable CLE 2 RST INT 15 INT Interrupt SPI Chip Select CS 3 CS RX 14 NC SPI Clock SCK 4 SCK TX 13 NC SPI Data OUT SDO 5 MISO SCL 12 NC SPI Data IN SDI 6 MOSI SDA 11 NC 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 INT - Interrupt LED Indicator JP1 VCC SEL Left Logic Level Voltage Sel