Time, RTC & Clocks

The DS1307 and DS3231 are two of the most commonly used real-time clock (RTC) ICs in Arduino and embedded projects. While they are similar in function and even share the same I2C address, their performance and internal design are very different. This article compares both RTCs and helps you decide which one is the better […]

Handling time in embedded systems is not only about keeping accurate time, but also about storing, transmitting and processing it efficiently. One of the most widely used representations is Unix time, also known as epoch time. This article explains Unix time, common time formats and how they are used in embedded systems. What Is Unix

Real-time clocks (RTCs) are designed to keep time continuously, even when the main system power is removed. This is made possible by a backup power source, typically a coin cell battery or, in some designs, a supercapacitor. Choosing the right backup method is critical for reliable long-term timekeeping. Why RTC Backup Power Is Needed When

In professional and robust embedded systems, relying on a single time source is often not sufficient. Each method—RTC, GPS, NTP and atomic clock receivers—has strengths and weaknesses. By combining multiple time sources, you can build systems that are both highly accurate and reliable under all conditions. Why Combine Time Sources? No single method is perfect

Most real-time clock (RTC) modules such as the DS1307 and DS3231 use the I2C bus for communication. While I2C is simple and widely supported, many practical issues arise from incorrect wiring, missing pull-up resistors or bus conflicts. This guide explains how to connect RTC modules correctly and troubleshoot common problems. Basic I2C Wiring I2C uses

Even high-quality real-time clocks (RTCs) such as the DS3231 are not perfectly accurate. Over time, small frequency errors accumulate and cause measurable drift. In applications where higher precision is required, software-based calibration can significantly improve accuracy. This article explains how drift occurs and how to correct it using calibration techniques. What Is Clock Drift? Clock

Atomic clock receivers allow electronic systems to synchronize automatically with highly accurate national time standards. These systems use long-wave radio signals transmitted at around 60 kHz and are widely used in radio-controlled clocks and precision timing devices. This article explains how these signals work and how they are used in embedded systems. What Are 60

In battery-powered and energy-efficient designs, power consumption is a critical factor. Real-time clocks (RTCs) are designed to operate with extremely low current, but the overall system design determines how efficient a clock circuit really is. This article explains how to design ultra-low power clock systems and avoid common pitfalls. Why Power Consumption Matters Battery-powered devices

The DCF77 time signal is the primary atomic clock broadcast for Europe and is widely used in radio-controlled clocks and industrial timing systems. Transmitted from Germany at 77.5 kHz, it provides highly accurate time information derived from atomic clocks. DCF77 is one of the most important long-wave time signals worldwide and has been in continuous

The performance of atomic clock receivers depends heavily on the antenna. At frequencies such as 60 kHz and 77.5 kHz, traditional wire antennas are impractical due to the extremely long wavelength. Instead, ferrite rod antennas (also called loopstick antennas) are used to capture these signals efficiently. This article explains how these antennas work and how