Fermion: DS3232 Precise RTC (Breakout)

The Fermion: DS3232 Precise RTC Breakout is a high-accuracy real-time clock module featuring an integrated crystal resonator and active temperature compensation. Equipped with 236 bytes of ultra-low-power SRAM, it is ideal for makers, students, and engineers designing reliable IoT dataloggers and embedded timing systems.

Temperature-compensated precision timing

The onboard DS3232 integrates a crystal resonator and temperature compensator to minimise drift, maintaining a timing accuracy of ±3.5ppm (approximately ±0.3024 seconds per day) across temperatures from -40°C to +85°C.

Connection and board layout

The breakout communicates via standard I2C at address 0x68 and operates on a 3.3V to 5.5V supply. It ships with a 2.54mm 7-pin header for straightforward connection to microcontrollers and development boards.

Compact breakout form factor

Measuring just 22.5 x 21mm, this compact module draws a low timing current of 1500nA, making it easy to embed into space-constrained projects.

Integrated 236-byte SRAM storage

The module includes 236 bytes of built-in SRAM that retains data with exceptionally low power consumption. This provides useful non-volatile storage for small data packets, configuration flags, or event logs in IoT applications.

Comprehensive calendar and alarm functions

The RTC tracks seconds, minutes, hours, day, date, month, and year with automatic leap-year corrections from 1970 to 2100 in 12-hour or 24-hour modes. It also includes two programmable time-of-day alarms and a programmable square-wave output.

Battery backup and reset support

A dedicated battery input accepts a standard CR1220 coin cell to maintain continuous timekeeping when primary power is removed. Additionally, the RST pin can function as a push-button input for microprocessor reset.

Downloads & documentation

• Product wiki (DFRobot)