RTC 12 Click Board™

How Does the RTC 12 Click Board™ Work?

The RTC 12 Click Board™ as its foundation uses the DS1343, a low-current RTC that consumes an extremely low timekeeping current permitting longer life from a backup supply source from Maxim Integrated. The devices provide a full binary-coded decimal clock calendar accessed by a simple serial interface. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The month's end date is automatically adjusted for months with fewer than 31 days, including corrections for leap year through 2099. The clock operates in either a 24-hour or 12-hour format with an AM/PM indicator.

As performed on this Click board™, the most common configuration is a battery-backed up RTC, which maintains time and may hold data in 96 bytes of NV RAM provided for data storage. In addition to the DS1343, the RTC 12 Click is equipped with a button cell battery holder compatible with the 3000TR battery holder, suitable for 12mm Coin Cell batteries. Furthermore, it also has a built-in temperature-compensated power-sense circuit that detects power failures and automatically switches to the backup supply, thus allowing for uninterrupted operation.

The DS1343 communicates with MCU using the standard SPI serial interface that supports modes 1 and 3 with a maximum frequency of 4 MHz. It also provides two programmable time-of-day alarms. Each alarm can generate an interrupt on a programmable combination of seconds, minutes, hours, and days, available on the INT pin of the mikroBUS™ socket. The interrupt selection can be made by positioning the SMD jumper labelled INT SEL to an appropriate position. Both interrupt outputs operate when the device is powered by mikroBUS™ power rails or backup supply voltage.

In addition to the features mentioned above, the user can use another additional indicator routed to the AN pin of the mikroBUS™ socket labelled as PF to indicate a loss of a primary power supply, VCC from mikroBUS™ power rails.

The RTC 12 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. In addition, 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

PINOUT DIAGRAM

This table shows how the pinout on RTC 12 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Power-Fail Indicator	PF	1	AN	PWM	16	NC
NC	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

RTC 12 CLICK ELECTRICAL SPECIFICATIONS