Project #10: ESP8266 Thing – Precision RTC – Mk04

DS3231 Precision RTC FeatherWing

A Feather board without ambition is a Feather board without FeatherWings! This is the DS3231 Precision RTC FeatherWing: it adds an extremely accurate I2C-integrated Real Time Clock (RTC) with a Temperature Compensated Crystal Oscillator to any Feather main board. This 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.

With a CR1220 12mm lithium battery plugged into the top of the FeatherWing, you can get years of precision timekeeping, even when main power is lost. Great for datalogging and clocks, or anything where you need to really know the time.


1 x SparkFun ESP8266 Thing
1 x SparkFun FTDI Basic Breakout – 3.3V
1 x DS3231 Precision RTC FeatherWing
1 x RHT03 Humidity and Temperature Sensor
6 x Jumper Wires 3″ M/M
3 x Jumper Wires 6″ M/M
1 x Full-Size Breadboard
1 x SparkFun Cerberus USB Cable

SparkFun ESP8266 Thing

LG1 – Digital 5
RHT – Digital 4
SDA – Digital 2
SCL – Digital 14
VIN – +3.3V






Don Luc

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