AT89C2051 4-Digit LED Clock Kit

This hands-on DIY electronics kit features a compact PCB-based design with dimensions of approximately 75 × 50 mm and a lightweight construction suitable for educational bench use. It includes all essential components to assemble a functional 4-digit digital clock: AT89C2051 microcontroller (8051 architecture), common-anode 4-digit 7-segment LED display, crystal oscillator (11.0592 MHz), capacitors, resistors, transistors, push buttons, and supporting passive components. The kit uses through-hole components for beginner-friendly soldering and is powered by a standard 5V DC supply. Firmware is pre-programmed onto the AT89C2051 to deliver accurate timekeeping via software-driven multiplexed display control. The clock implements hour/minute display in 12-hour format with adjustable time setting using two tactile buttons — one for mode selection and one for incrementing values. Timekeeping relies on the microcontroller’s internal timer with calibration based on the 11.0592 MHz crystal, delivering stable operation under typical lab conditions. Display brightness is fixed but clearly legible in indoor lighting. Designed specifically for structured learning, this kit supports step-by-step assembly in classroom labs, self-paced study, or makerspace workshops. It serves as a foundational project for understanding microcontroller I/O control, multiplexed LED driving, timer interrupt handling, and basic firmware interaction — all without requiring prior programming experience.