Suggested Part: DS3231 (I2C), DS3234 (SPI) The DS3234 has the distinction of using an SPI interface instead of I2C. It also packs in 256 bytes of user-addressable RAM.

DS3231 RTC 11 Articles . ... Under the wood, there are a pair of Arduino Nanos, an mp3 decoder board, and an RTC module. Why two Nanos, you ask? Well, the IR interrupts kept, ...