RTC Module Reviews: Find the Best Real-Time Clock for You

Key Takeaway

  • RTC modules help keep track of time, even during power outages.
  • The DS3231 offers high accuracy and extra features.
  • The DS1307 is a more budget-friendly option for basic needs.

Real-time clock (RTC) modules play a crucial role in keeping track of the current time, even during power outages. Many hobbyists and engineers enjoy incorporating these modules into their electronic projects for added reliability. But which RTC module stands out among the rest? Readers can discover some of the best options available and gain insights from user experiences. With so many choices, it’s essential to find the right module that meets specific needs. Keep reading to explore the top RTC modules and learn what makes them popular among users. (1)

Credits: SetNFix

1. DS3231 RTC Module

The DS3231 is a favorite among users for its impressive accuracy. This module keeps time with an error margin of just about one minute per year! It uses a straightforward I2C connection method, making it easy to connect with microcontrollers. Plus, it features a built-in temperature sensor that helps maintain accuracy across different temperatures.

  • Price: Typically around $17.99, and users buying in bulk can often find discounts.
  • User Feedback: Many users rave about this module’s performance. They appreciate how it keeps time accurately, even when the Arduino is powered off. Its versatility with various microcontrollers also makes it a go-to choice for different projects.

The DS3231 shines in projects that need reliable timekeeping, making it perfect for clock builds and other electronic applications.

2. DS1307 RTC Module

The DS1307 is a budget-friendly option that delivers reliable performance. Like the DS3231, it utilizes the I2C connection, making it easy to integrate with devices like Raspberry Pi and Arduino. This module can keep track of time even during power outages, making it suitable for various electronic projects.

  • Price: Usually priced between $6.95 and $9.40, depending on the vendor.
  • User Feedback: Users generally find it performs well for basic tasks. While some note that it might not be as precise as the DS3231, many appreciate its reliable performance for simpler applications.

For hobbyists and beginners, the DS1307 offers good functionality at a lower price. It’s a popular choice for many projects, especially for those just getting started.

3. PCF8523 RTC Module

The PCF8523 stands out as a low-power option, making it ideal for battery-operated projects. This module offers the flexibility of displaying time in both 12-hour and 24-hour formats, catering to users’ preferences.

  • Price: Generally available for around $13.45.
  • User Feedback: Users appreciate the PCF8523’s low power consumption, noting its reliable performance with battery backup. This feature ensures it keeps time accurately, even during power interruptions.

The PCF8523 is perfect for projects that need to conserve battery life. Users report that it maintains accurate time over long periods, making it a solid choice.

4. MCP79412 RTC Module

The MCP79412 is unique because it includes EEPROM storage, allowing users to save small amounts of data—handy for many applications. It also has a built-in oscillator to ensure accurate timekeeping.

  • User Feedback: Overall, feedback for the MCP79412 is positive, with users stating it effectively maintains time during power outages. However, it has fewer reviews than the more popular DS3231 and DS1307.

For those seeking added features, the MCP79412 is a good option. Its data storage capability enhances its functionality, making it useful for various projects.

Key Considerations When Choosing an RTC Module

When selecting the right RTC module, users should consider several essential factors:

  • Accuracy: For those who prioritize precise timekeeping, the DS3231 stands out as the top choice. Its accuracy is superior to other modules, making it ideal for time-sensitive projects.
  • Power Consumption: Projects needing long battery life should look for low-power options like the PCF8523. Choosing a module with low power consumption helps extend battery life significantly.
  • Interface Compatibility: It’s crucial to ensure that the chosen module easily connects with the microcontroller. Most RTC modules utilize the common I2C interface, which is known for its simplicity and ease of use.
  • Extra Features: Some RTC modules come with additional functionalities. For instance, features like built-in temperature sensors or data storage can be beneficial, depending on the project’s needs.

By keeping these considerations in mind, anyone can find the right RTC module that meets their requirements, helping projects run efficiently and accurately.

General Overview of RTC Modules

RTC modules, or real-time clock modules, are vital components in many electronic projects. They keep track of the current time and date, even during power outages, which is crucial for applications that rely on precise timing, such as clocks, timers, and data logging. Most RTC modules connect via a method called I2C, making it easy to link them with microcontrollers like Arduino and Raspberry Pi.

Using an RTC module is typically straightforward. Once hooked up, these modules can maintain time with impressive accuracy. Many come with a built-in battery backup that ensures they keep running even when the power goes out. Some models add extra features, such as temperature sensors, to enhance their reliability. Overall, RTC modules are essential for anyone seeking dependable timekeeping in their projects.

User Experiences and Reviews

User experiences with RTC modules reveal a mix of positive feedback and a few common challenges.

  • Positive Aspects: Many users sing the praises of the DS3231 module. They frequently highlight its ease of setup and seamless integration with their projects. Users appreciate its ability to keep time accurately, even when powered off, which is especially important for Arduino systems. Many report having no problems with the DS3231 and recommend it for a range of applications, from simple clocks to more intricate data logging setups.
  • Common Complaints: However, some users have faced battery life issues with certain modules, noting they had to replace batteries more often than anticipated. Additionally, a few mentions exist about needing extra tools or jumper wires for proper connections. While these complaints aren’t widespread, they indicate that some users might encounter challenges during setup. Overall, feedback on RTC modules remains largely positive, with many users enjoying their reliability and ease of use.

Availability and Pricing

RTC modules are easy to find online, making them accessible for anyone interested in electronics. Prices vary based on the model and features, generally ranging from $6.00 to $35.00. (2)

  • DS3231 Pricing: The DS3231 typically retails for around $17.99. This price reflects its high accuracy and added features, such as built-in temperature sensors and battery backup. Many users feel this price is reasonable considering the reliability and performance the module offers.
  • DS1307 Pricing: The DS1307 is a more budget-friendly option, often available for under $10. This makes it a great choice for beginners or those tackling simpler projects. Despite its lower price, it still provides effective timekeeping for basic applications.

With numerous options available, buyers can easily select a module that fits their project needs and budget. Overall, RTC modules are both accessible and affordable, making them a smart choice for enhancing timekeeping in various electronic projects.

FAQs

How do real time clock modules like the DS3231 RTC and DS1307 RTC compare in terms of accuracy?

The DS3231 real time clock offers high accuracy and temperature compensation, while the DS1307 real time clock is more basic. The DS3231 real time clock module keeps time better and handles leap years automatically. Both work with a coin cell battery for battery backup and can keep track of the current time, date, and day of the week.

What should I check in customer reviews when buying an RTC module for Raspberry Pi or Arduino Uno?

Look for reviews that mention how well it works with the i2c interface, if it keeps track of the current time reliably, and battery backed performance. Good reviews often discuss how the module includes proper 3v and 5v power support, works great with different boards, and maintains accurate time.

What’s included in a typical RTC breakout board battery backup system?

A standard board battery backup usually comes with a battery holder for a coin cell battery or lithium battery. The module includes connections for the i2c bus, often has a square wave output option, and might have an ohm resistor for power regulation. Most support both 5v power and low power operation.

How do I make sure my RTC clock maintains high precision time keeping?

For high precision and high accuracy time keeping, especially with a high accuracy DS3231, proper setup is crucial. This includes stable power supply connections, correct battery backup installation, and regular checks through the serial monitor to ensure it can keep time accurately.

What’s the easiest way to set the time on an RTC module for Raspberry Pi?

The rtc module connects via the i2c interface, and you can set the time using simple commands. Most modules based on the maxim high precision chips like the DS3231 chip or DS1307 rtc module make it easy to keep track of the current year and time through basic programming.

How long does a backup battery typically last in an RTC IC?

A coin cell battery or other battery backed solution can keep time for several years in low power mode. The actual lifespan depends on factors like temperature and usage, but most rtc clock modules with proper battery backup can maintain time keeping for 3-5 years.

What information can I find in the data sheet for an RTC module?

The data sheet typically covers power supply requirements (like 3v and 5v compatibility), timekeeping accuracy, and whether it handles leap years automatically. It also explains features like temperature compensation, auto renewal packs support, and how to use the square wave output.

How do RTC modules compare to GPS receiver modules for keeping accurate time?

While GPS receiver modules provide extremely accurate time by syncing with satellites, rtc modules offer a more power-efficient solution for projects that just need to keep the time locally. RTCs with battery backup work well even without constant power, making them ideal for projects that need to keep track of time independently.

Conclusion

RTC modules, such as the DS3231 and DS1307, are widely favored for various electronic projects. They provide accurate timekeeping and are user-friendly. Whether seeking high accuracy for complex applications or a budget-friendly option for simpler tasks, there’s an RTC module suited to every need. With their reliability and ease of integration, these modules are excellent choices for anyone looking to enhance timekeeping in their electronic designs.

References

  1. https://www.jameco.com/Jameco/Blog/choosing-the-right-real-time-clock-chip-or-module.html 
  2. https://hobbycomponents.com/rtc/348-ds1302-real-time-clock-module 
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Nathan Griffin

I’m Nathan Griffin, the founder and owner of Crocodile RTC. My passion for electronics and precision engineering has driven me to build a business that specializes in one of the most critical yet often overlooked components—Real-Time Clock (RTC) modules. With years of experience in the field, I’ve developed a deep understanding of the intricacies behind accurate timekeeping, and I’m committed to delivering products that meet the highest standards of reliability.

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