MIKROE RTC 13 Click

MIKROE RTC 13 Click is a compact add-on board that accurately keeps the time of a day. This board features the PCF2123 an SPI configurable real-time clock/calendar optimized for low power operations from NXP Semiconductors. The PCF2123 provides year month day weekday hours minutes and seconds based on a 32.768kHz quartz crystal. Data is transferred serially via an SPI interface 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 in addition to a programmable square-wave clock output. This Click board™ is suitable for various time-keeping applications including high-duration timers metering daily alarms low standby power applications and many more. RTC 13 Click is supported by a mikroSDK compliant library which includes functions that simplify software development. RTC 13 Click 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 this 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. This 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.