Integrating Real Time Clocks in Microcontroller Applications
Certain microcontroller applications, especially those involving data logging or tracking, necessitate accurate time and date records alongside collected data. Real Time Clock (RTC) chips like the DS1307 IC, equipped with battery backup, provide this crucial information. Integrating this chip into designs is remarkably straightforward, demanding only a minimal number of external components. The software programming process is uncomplicated and enjoys extensive support across various programming environments. Intrinsic functions, header files, and libraries tailored for this device are readily available, making it easily accessible for developers. A plethora of programming examples can be found online, showcasing the chip’s versatile applications.
Programming the RTC Chip and its Practical Solution
To make the Real Time Clock (RTC) chip operational, it initially requires programming with the current time and date information. Remarkably, this information persists and updates even when the external circuitry is powered down, thanks to a keep-alive battery. Programming demands a connection to a keyboard and display, but this additional hardware is necessary only for this one-time configuration. The proposed solution addresses this challenge by consolidating the IC, battery, crystal, and peripheral components onto a compact plug-in PCB.
The circuit comprises a small prototyping perf board featuring the IC, crystal, battery, a decoupling capacitor (C1), and optionally, two pull-up resistors for open collector outputs. The design is completed with an IC socket boasting extra-long pins or two modular connector strips. The resulting RTC module (as depicted in the photo) is self-contained, allowing it to be seamlessly moved from one circuit to another via its extended pins without losing track of time and date. The sole requirement in the target system is space for an 8-way Dual In-Line (DIL) socket, appropriate wiring, and software to retrieve the time information.
Cost-Effective Solution for Hardware and Software Implementation
This approach offers a significant advantage: it minimizes both hardware and software expenses in the target system, as it solely needs to read the time and date information. The additional hardware and software necessary for setting the time and date can be designated to a separate system, possibly a dedicated breadboard design. Once programmed, the functioning clock module can effortlessly be transferred to the target system, simplifying the overall process.