About this item
The ELECROW Crowtail‑RTC (Model CT0009RT) is a compact real‑time clock module designed for projects where accurate timekeeping is needed even when the main power is off. At its core is the DS1307 clock/calendar chip, which keeps track of seconds, minutes, hours, day, date, month, and year, adjusting automatically for months with fewer than 31 days and correcting for leap years. It connects over the I²C protocol (two‑wire: SDA, SCL), so it integrates smoothly with microcontrollers like Arduino, ESP32, etc., especially via the Crowtail base shield or any I²C port. What sets it apart is its low power consumption: it has a battery backup option (using a small coin cell battery, e.g. CR1220) that allows the clock to continue running when the main supply is disconnected. This makes it useful for applications like data loggers, clocks, alarms, or any system that needs to remember the correct time after being powered off. The module is small and lightweight, with standard Crowtail four‑pin connector (SCL, SDA, VCC, GND), so wiring is easy and clean. It’s ideal for hobbyists, students, or makers aiming to build time‑based control systems without relying on expensive or bulky clock ICs.
Specifications
| Operating Voltage |
5V DC |
| Backup Battery Voltage |
2.0 to 3.5V (coin cell, e.g. CR1220) |
| Interface |
I²C (SCL, SDA, VCC, GND) |
| Time Keeping |
Seconds, minutes, hours, day, date, month, year; automatic month‑length adjustment and leap‑year support |
| Dimensions |
~20.0 mm × 20.0 mm × 10.0 mm |
| Model / Chipset |
Based on DS1307 real‑time clock chip |
| Low Power Consumption |
Enough to keep clock running for over a month on backup battery when main power is off |
| Crowtail Compatibility |
Standard 4‑pin Crowtail connector for easy plug‑and‑play with Crowtail base shields |
