DS3231 Precision Real-Time Clock
Battery-backed precision RTC with TCXO. Keeps accurate time (±2ppm, < 1 minute/year drift) with built-in temperature sensor and dual alarms.
Say it to PAL
“What time is it, and how warm is it?”
The code PAL writes
const h = await p.read('qwiic-ds3231', 'hours');
const mins = await p.read('qwiic-ds3231', 'minutes');
const temp = await p.read('qwiic-ds3231', 'temperature');
p.log(`${h}:${String(mins).padStart(2, '0')} — ${temp}°C`);“Set an alarm for every day.”
The code PAL writes
await p.write('qwiic-ds3231', 'set_alarm1', { hours: 7, minutes: 30, seconds: 0 });
p.log('Alarm set for 7:30 AM');When to pick it
Best-in-class RTC for precision timekeeping. Use when accuracy matters or for data logging timestamps. Also provides a bonus temperature sensor.
Good to know
- Battery (CR2032) lasts 5-10 years in timekeeping mode. Replace if time is lost on power cycle.
- Temperature updates only every 64 seconds — not real-time.
About it
The DS3231 is a high-precision real-time clock with an integrated temperature-compensated crystal oscillator (TCXO) and battery backup. Accuracy of ±2ppm (less than 1 minute per year) across the full temperature range. Features two programmable alarms, a built-in temperature sensor (±0.25C resolution), 32KHz output, and aging register for fine-tuning. The gold standard for offline timekeeping in IoT projects.
Where to buy
Facts
Tested
It is in our catalog, but nobody has checked it on a real board. It may not work yet. Its driver is written, but it has not been tested on hardware yet.
I2C address
The DS3231 Precision Real-Time Clock answers at I2C address 0x68. The address is fixed.
Current
200 µA
The catalog lists a typical draw of 200 µA for the DS3231 RTC, copied from the maker’s description and not measured by Palpable.
Board size
25.4 × 17.78 mm
The DS3231 RTC board measures 25.4 × 17.78 mm and stands 4.6 mm tall with its parts. It has 2 mounting holes. These dimensions are from the maker’s mechanical drawing.
Chip
DS3231
Its real-time clock is the Analog Devices (Maxim Integrated) DS3231.
Free to reuse
Every fact here is open data under CC BY 4.0. Copy it into your own docs or code, and credit Palpable. Download it
This record was last changed on October 6, 2026.