The datasheet for the DS3231 explains that this part is an “Extremely Accurate I²C-Integrated RTC/TCXO/Crystal”. And, hey, it does exactly what it says on the tin! This Real Time Clock (RTC) is the most precise you can get in a small, low-power package.
Most RTCs use an external 32kHz timing crystal that is used to keep time with low current draw. And that’s all well and good, but those crystals have slight drift, particularly when the temperature changes (the temperature changes the oscillation frequency very very very slightly but it does add up!) This RTC is in a beefy package because the crystal is inside the chip! And right next to the integrated crystal is a temperature sensor. That sensor compensates for the frequency changes by adding or removing clock ticks so that the timekeeping stays on schedule.
This is the finest RTC you can get, and now we have it in a compact, breadboard-friendly breakout. With a coin cell plugged into the back, you can get years of precision timekeeping, even when main power is lost. Great for data-logging and clocks, or anything where you need to really know the time. A coin cell is required to use the battery-backup capabilities! We don’t include one by default, to make shipping easier for those abroad, but we do stock them so pick one up or use any CR1220 you have handy.
To make life easier so you can focus on your important work, we’ve taken the sensor and put it onto a breakout PCB along with support circuitry to let you use it with 3.3V (Feather/Raspberry Pi) or 5V (Arduino/ Metro328) logic levels. Additionally, since it speaks I2C you can easily connect it up with two wires (plus power and ground!). We’ve even included SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don’t even need to solder! QT Cable is not included, but we have a variety in the shop. Just wire up to your favorite micro and you can use our CircuitPython/Python or Arduino drivers to easily interface with the DS3231.
Comes as a fully assembled and tested breakout plus a small piece of header. You can solder header in to plug it into a breadboard, or solder wires directly.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.