# DS3231M MEMS Precise RTC

**Type:** Product page · **SKU:** DFR0641 · **Brand:** [DFRobot](https://core-electronics.com.au/brands/dfrobot-australia)
**Page:** https://core-electronics.com.au/ds3231m-mems-precise-rtc.html ([markdown](https://core-electronics.com.au/ds3231m-mems-precise-rtc.html.md))

This precise RTC adopts DS3231M chip, which integrates MEMS resonator and temperature compensator. Compared to quartz crystal clock, the real-time clock reduces...

## Pricing

- **Price:** $11.75 (inc GST) — $10.68 AUD, exc GST
- **Quantity discounts:** 6+ $10.15 (exc GST) · 12+ $9.72 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 7 today, and up to 1 more in 8–12 days.

## Restrictions

Restrictions apply to this equipment as it uses button/coin cell batteries:

- The equipment is intended to be used in trades, professions or industries
- The equipment is not intended for sale to the general public
- The equipment is not intended to be used where children are present
- You are aware that this equipment may not meet child safety testing requirements as it is not intended to be used by consumers or general public, but rather, is intended to be used in trades, professions or industries in conjunction with the limitations and restrictions listed above
- You are aware that these restrictions are due to a change in [A](https://www.accc.gov.au/media-release/businesses-on-notice-as-mandatory-button-battery-laws-commence)[ustralian legislation in 2022](https://www.accc.gov.au/media-release/businesses-on-notice-as-mandatory-button-battery-laws-commence) for button/coin cell batteries
 
![Button Battery Warning](https://core-electronics.com.au/attachments/uploads/iec-button-battery.png)

A declaration of use will need to be submitted during checkout.

## Description

This MEMS Precise RTC Breakout Board adopts DS3231M chip, which integrates MEMS resonator and temperature compensator. Compared to quartz crystal clock, the real-time clock reduces the risk of mechanical failure. Therefore, it can be used in a highly vibrating environment.Within -45°C to +85°C, the accuracy of the DS3231M is ±5ppm (±0.432 s/D).

The RTC based on MEMS has already passed both shock tests and vibration tests that certified by ACE-Q100. It can withstand 2900g mechanical shock (JESD22-B104C Condition-H) and 20g variable frequency vibration (JESD22-B103B Condition-1).

The DS3231M can be powered by a coin cell battery and can still maintain accurate timing even the mains are disconnected.[ RTC ](https://www.dfrobot.com/category-232.html)provides information about seconds, minutes, hours, days, months, and years. It can automatically adjust the end date of the month and the leap year correction. The clock format can be 24 hours or 12 hours with AM/PM indication. It provides two programmable calendar alarms and one 1Hz square wave output. In addition, the RST check pin can be used as a key input for microprocessor reset.

**Note:** According to the latest Air Transport Regulations, the batteries, magnets and liquids transport will be very stringent, so the cell battery CR1220 will not come with the module any more. Please buy it from the local supermarket.

**DS323X Selection Guide**

| **Product Name** | **Fermion: DS3231M MEMS** **Precise RTC Module** | **Fermion: DS3231 Precision RTC Module** | **Fermion: DS3232** **Precision RTC Module** |
|---|---|---|---|
| **SKU** | **[DFR0641](https://www.dfrobot.com/product-1991.html)** | **[DFR0819](https://www.dfrobot.com/product-2313.html)** | **[DFR0821](https://www.dfrobot.com/product-2304.html)** |
| **Storage** | None | None | 236Byte |
| **Integrated R****esonator** | MEMS | XTAL | XTAL |
| **Timing Current** | 2000nA | 840nA | 1500nA |
| **Timing Precision** | ±5ppm (±0.432s/d) | ±3.5ppm (±0.3024s/d) | ±3.5ppm (±0.3024s/d) |
| **Operating Voltage** | 3.3V-5.5V | 3.3V-5.5V | 3.3V-5.5V |
| **Operating Temperature** | -45°C ~ 85°C | -40°C ~ 85°C | -40°C ~ 85°C |
|  | Integrated MEMS resonatr, reducing the risk of mechanical failure, suitable for use in strong and frequent vibration. | A RTC module with integrated crystal resonator, featuring a higher precision and a lower power consumption, suitable for use in the occasion in demand of high precision and low power. | A RTC module with integrated crystal resonator, equipped with 236Byte SRAM storage inside, enabling it to store data at an extremely low power consumption, suitable for low-power loT applications requiring real-time clock. |

###  Features

- High anti-vibration
- Internal MEMS resonator and temperature compensator
- High precision: ±5ppm (±0.432 s/D) at -45°C to +85°C
- Clock calendar
- 2 programmable calendar alarms

###  Specification

- Operating Voltage: 3.3V-5.5V
- I2C Address: 0x68
- Timing Range: 1970~2100 year
- Operating Temperature: -40°C to +85°C
- Timing Precision: ±5ppm (±0.432 s/D)
- Dimension: 22.5\*21mm / 0.886\*0.827inch

###  Projects

Project 1: [**Making an Arduino OLED Ring Clock**](https://community.dfrobot.com/makelog-308274.html)

The hardwares you need to do this project:

[0.91”128x32 I2C OLED Display](https://www.dfrobot.com/product-2019.html)x1

[DS3231M MEMS Precise RTC](https://www.dfrobot.com/product-1991.html)x1

[Beetle](https://www.dfrobot.com/product-1075.html)x1

3.7V Lithium Battery Charger x1

1000mah 3.7v Lithium Battery x1

Needle x1

A piece of elastic braid tape

###  Documents

22. [Product wiki](https://wiki.dfrobot.com/DS3231M%20MEMS%20Precise%20RTC%20SKU:%20DFR0641)
###  Parts List

24. DS3231M MEMS Precise RTC x1
25. 2.54-7P Pin x1

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/d/f/dfr0641-1.jpg)