SparkFun Real Time Clock Module - RV-1805 (Qwiic)

Stay in sync with the SparkFun Real Time Clock (RTC) Module, a Qwiic-enabled breakout board for the RV-1805 chipset. This RTC module operates with ultra-low power, using only about 22nA in its lowest power setting. It utilizes a supercapacitor for backup power, providing plenty of charge and discharge cycles without any degradation. All communication is enacted exclusively via I²C, using the Qwiic system for easy, solder-free connections. However, 2.54mm-spaced pins are also available for those who prefer using a breadboard.

One of the unique features of the RTC module is the built-in RV-1805 which houses two internal oscillators: a 32.768kHz tuning fork crystal and a low power RC based oscillator. The module can automatically switch between the two, using the more precise crystal to correct the RC oscillator every few minutes. This allows the module to maintain a very accurate date and time, with the worst case being +/- about three minutes over a year. The RV-1805 also has a built-in trickle charger, fully charging the RTC in under 10 minutes once it's connected to power. Additionally, the RV-1805 can switch power to other systems, enabling it to directly turn on or off power-hungry devices such as a microcontroller or RF engine.

If you need longer power duration, you have the option to add a battery to the board. The supercapacitor can keep the board running for around 35 days, but if you need more time, you can solder on an external battery. This means the board can sit with no power or connection to the outside world and still maintain the current hour/minute/second/date.

Note: The I²C address of the RV-1805 is 0x69 and is hardware defined. A multiplexer/Mux is required to communicate to multiple RV-1805 sensors on a single bus. If you need to use more than one RV-1805 sensor, consider using the Qwiic Mux Breakout.

With the SparkFun Qwiic connect system, you're entering an ecosystem of I²C sensors, actuators, shields and cables designed to make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector, reducing the amount of required PCB space. Plus, polarized connections mean you can’t hook it up wrong.

Features:

• Operating Voltage (Startup): 1.6V - 3.6V
• Operating Voltage (Timekeeping): 1.5V - 3.6V
• Operating Temperature: -40°C - 85°C
• Time Accuracy: ±2.0 ppm
• Current Consumption: 22nA (Typ.)
• I²C Address: 0xD2
• Supercapacitor for Backup Power
• 2x Internal Oscillators
• 2x Qwiic Connectors

Documents:

• Schematic
• Eagle Files
• Hookup Guide
• Datasheet (RV-1805)
• Datasheet (DSK-414)
• Application Manual (RV-1805)
• Qwiic Page
• Arduino Library
• GitHub