Electronics

Real Time Clock RTC Module DS3231SN ChronoDot V2.0 I2C

AED 29.40

1

Description

The ChronoDot RTC V2 is a real-time clock module that uses the DS3231 temperature-adjusted RTC controller. It is very precise and comes with an internal crystal and a switching bank of tuning capacitors that keep the frequency steady, resulting in less than a minute of drift per year. It is suitable for time-critical applications that cannot be synced to an external clock on a regular basis. The module can be powered by a 2.3 to 5.5 V DC power supply and has low power consumption in both active and timekeeping modes. The I2C interface is simple and compatible with Arduino.

 

Package Includes:

  • 1 x ChronoDot RTC V2

 

Features:

  1. Temperature-Compensated Real-Time Clock: The ChronoDot RTC V2 is based on the DS3231 temperature-adjusted RTC, which is highly precise and stable due to its TCXO (Temperature-Compensated Crystal Oscillator) feature. It has an internal crystal and a switching bank of tuning capacitors that constantly monitor the crystal's temperature and adjust the frequency to maintain high accuracy.
  2. High Accuracy: The ChronoDot RTC V2 has an accuracy of ± 3.5ppm (parts per million) at -40C to +85C temperature range, which translates to less than a minute of deviation per year. This level of accuracy makes the ChronoDot ideal for time-critical applications that require precise timekeeping.
  3. Long Battery Life: The module comes with a CR1632 battery that can last up to 8 years if the I2C interface is only utilized when the device is powered by 5V. The battery is user-replaceable and can be easily inserted into the top-mounted battery holder.
  4. Simple I2C Interface: The ChronoDot RTC V2 has a simple I2C interface that is nearly equivalent to the register locations of the widely used DS1337 and DS1307 RTCs. Existing code for the Arduino, Basic Stamp, Cubloc, and other controllers can be used without any modifications.
  5. Wide Voltage Range: The module can operate with a power supply voltage range of 2.3 to 5.5 V DC, making it compatible with both 3.3V and 5V systems.
  6. Small Form Factor: The ChronoDot RTC V2 has a compact PCB size of 1.2 inches in diameter, with pin spacing of 0.1 inches and header spacing of 0.9 inches. It can be easily plugged into a typical solderless breadboard and features mounting holes for attaching to a chassis.
  7. Additional Pins: The module has additional pins, including BAT, RST, SQW, and 32K. The BAT pin is directly linked to the battery voltage and can be used to monitor the battery's health. The RST pin is an active-low signal that can be used for resetting a microcontroller in the case of a power failure or an external circumstance such as a reset button. The SQW pin can be set to generate a square wave signal or trigger an alarm, and the 32K pin outputs a 32768 Hz clock signal that can be used as an accurate oscillator reference for external devices.

 

Description:

The ChronoDot RTC V2 is a real-time clock module that is based on the DS3231 temperature-compensated RTC, which is known for its high precision and accuracy. The device includes an internal crystal and a switching bank of tuning capacitors, which work together to keep the frequency stable. This means that the ChronoDot will drift by less than a minute per year, making it an ideal choice for time-critical applications that require accurate timekeeping over long periods of time. The device can be easily integrated into a wide range of projects, thanks to its simple I2C interface. The register locations of the ChronoDot are nearly identical to those of the widely used DS1337 and DS1307 RTCs, which means that existing code for these controllers should work without any modification. The ChronoDot can be powered by a range of voltages, from 2.3V to 5.5V, which makes it compatible with a variety of systems. The ChronoDot RTC V2 is also designed to be highly reliable. a CR1632 battery used to power the module which can last for at least 8 years if the I2C interface is only used when the device is powered by 5V. Additionally, the device features a top-mounted battery holder, which makes it easy to replace the battery when necessary. 

 

Principle of Work:

 

The ChronoDot RTC V2 is a real-time clock (RTC) module that is based on the DS3231SN temperature compensated RTC controller from Maxim Integrated. The DS3231SN uses an internal crystal oscillator and a switching bank of tuning capacitors to keep its frequency accurate over a wide range of temperatures. The internal oscillator is designed to have a high Q factor, which means that it has a low phase noise and can maintain its frequency with high precision. The switching bank of tuning capacitors allows the DS3231SN to adjust the frequency of the oscillator to compensate for changes in temperature. By continuously monitoring the temperature of the crystal, the DS3231SN can adjust the tuning capacitors to keep the frequency of the oscillator stable. The DS3231SN also includes a temperature sensor that allows it to compensate for changes in temperature that might affect the accuracy of the oscillator. By measuring the temperature of the crystal and compensating for its effects on the oscillator frequency, the DS3231SN can maintain its accuracy even in environments with varying temperatures. The ChronoDot RTC V2 connects to a microcontroller or other device using the I2C interface. It requires two pull-up resistors on the SDA and SCL lines to communicate properly with other I2C devices on the same bus. It is powered by a CR1632 battery and can operate on a voltage range of 2.3V to 5.5V. The module also features a square wave output that can be used for generating interrupts or other timing signals, and it includes a reset pin that can be used to reset a microcontroller in the event of a power failure or other external event.

 

Pinout of the Module:

  • VCC: This pin is used to provide power to the module. It requires a voltage of 3.3V to 5.5V and can be connected to a power supply or a microcontroller.
  • GND: This pin is connected to ground and is used as a reference for all other signals.
  • SCL: This is the I2C clock pin and is used to synchronize data transfers between the module and a microcontroller. It operates at a frequency of up to 400kHz.
  • SDA: This is the I2C data pin and is used to transfer data between the module and a microcontroller. It is bidirectional and is used for both reading and writing data.
  • SQW/INT: This pin can be configured to function as either an output signal or an input signal. It can generate a square wave signal with a frequency between 1Hz to 32.768kHz, which can be used as a clock signal for other devices. Alternatively, it can be configured as an interrupt signal to indicate events such as alarm conditions or changes in the status of the module.
  • 32K: This pin provides a 32.768kHz clock signal, which can be used as a reference for other devices.
  • RST: This pin is used to reset the module. It is an active-low input and is typically pulled high with a resistor.
  • VBAT: This pin is used to provide power to the module's backup battery. It requires a voltage between 2.0V and 3.5V and is typically connected to a small lithium-ion battery to provide backup power in case the main power supply is lost.

 

Applications: 

  1. Electronic instruments: The module can be used in electronic instruments that require precise time measurement and synchronization, such as oscilloscopes, signal generators, and frequency counters.
  2. Data loggers: The module can be used in data loggers to record accurate time and date information along with other measurements.
  3. Automation systems: The module can be used in automation systems that require precise timing and scheduling, such as lighting control, temperature control, and industrial control systems.
  4. Security systems: The module can be used in security systems that require accurate time synchronization for events, such as access control and CCTV systems.
  5. Communication systems: The module can be used in communication systems that require precise timing and synchronization, such as wireless communication systems and network switches.
  6. Robotics: The module can be used in robotics applications that require precise timing for control and synchronization of movements.

 

Circuit:

 

  • VCC pin on the module to 5V pin on the Arduino
  • GND pin on the module to GND pin on the Arduino
  • SDA pin on the module to A4 pin on the Arduino
  • SCL pin on the module to A5 pin on the Arduino

 

Library:

To install the RTClib library on Arduino, follow these steps:

  1. Download the RTClib library from its GitHub page: https://github.com/adafruit/RTClib.
  2. Extract the downloaded file and rename the folder to "RTClib".
  3. Move the "RTClib" folder to the "libraries" folder of your Arduino installation directory.
  4. Open the Arduino IDE and go to Sketch -> Include Library -> RTClib to include the library in your project.

After installing the RTClib library, you can use it to interface with the ChronoDot RTC module or any other RTC module that uses the DS3231 chip.

 

Code:  

a simple Arduino code to read the time from the ChronoDot RTC V2 module and display it on the Serial Monitor:

#include "Wire.h"
#include "RTClib.h"

RTC_DS3231 rtc;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  rtc.begin();

  // Uncomment the line below to set the current time to the RTC
  // rtc.adjust(DateTime(__DATE__, __TIME__));

  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  if (rtc.lostPower()) {
    Serial.println("RTC lost power, lets set the time!");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  DateTime now = rtc.now();

  Serial.print(now.year());
  Serial.print('/');
  Serial.print(now.month());
  Serial.print('/');
  Serial.print(now.day());
  Serial.print(' ');
  Serial.print(now.hour());
  Serial.print(':');
  Serial.print(now.minute());
  Serial.print(':');
  Serial.print(now.second());
  Serial.println();

  delay(1000);
}

  • This is a simple Arduino sketch for using the RTClib library with the DS3231 RTC module. The code first includes the necessary libraries - "Wire.h" and "RTClib.h".
  • In the setup() function, the serial communication is initialized with a baud rate of 9600. The I2C communication is also initialized with the Wire.begin() function, and then the RTC module is initialized with the rtc.begin() function.
  • The code then checks if the RTC module is connected or not. If it is not connected, the code prints "Couldn't find RTC" and enters an infinite loop. If it is connected but has lost power, the code sets the current time with the rtc.adjust() function.
  • In the loop() function, the current date and time are obtained from the RTC module with the rtc.now() function. The date and time are then printed to the serial monitor with the Serial.print() and Serial.println() functions. Finally, there is a delay of 1000 milliseconds before the loop repeats.
  • This code can be used to display the date and time on the serial monitor in a continuous loop.

 

Technical Details:

Controller: Maxim DS3231SN
Function: Temperature-compensated RTC
Accuracy: ± 3.5ppm at -40C to +85C (~1 minute per year)
Power Supply: 2.3 to 5.5 V DC
Current: 200uA (active), 840nA (timekeeping)
PCB Size: 1.2 inches diameter
Pin Spacing: 0.1 inches
Header Spacing: 0.9 inches

 

Resources:

 

Comparisons:

 

 

The ChronoDot RTC V2 is based on the DS3231SN chip, so they share many similarities. However, there are a few differences between the ChronoDot RTC V2 and the DS3231 module:

  1. Size: The ChronoDot RTC V2 is a small module, measuring only 19mm x 16mm x 5mm. The DS3231 module, on the other hand, can vary in size depending on the manufacturer.
  2. Accuracy: Both modules are highly accurate, with the DS3231SN chip providing accuracy within ±2ppm, which is equivalent to ±1.5 seconds per month. However, the ChronoDot RTC V2 includes an oven-controlled crystal oscillator (OCXO), which provides even greater accuracy, with an error of only a few seconds per year.
  3. Features: The ChronoDot RTC V2 includes a battery-backed SRAM (static random-access memory) and EEPROM (electrically erasable programmable read-only memory), which can be useful for storing data even when the power is turned off. The DS3231 module does not include these features.
  4. Price: The ChronoDot RTC V2 is generally more expensive than the DS3231 module. This is due to its higher accuracy and additional features.

you can say, both modules are excellent choices for projects that require accurate timekeeping. The ChronoDot RTC V2 offers higher accuracy and additional features, while the DS3231 module is a more cost-effective option.