Digital clock AT89C2051 DIY Electronics Kit step by step Assembly

This project guide details the step-by-step assembly of a digital clock kit based on the AT89C2051 microcontroller (also known as C51). This compact and versatile microcontroller is perfect for a variety of DIY projects. Building this clock provides a hands-on learning experience in electronics assembly and basic microcontroller programming. The completed clock offers practical applications such as:

A simple, reliable timekeeping device for workshops or bedrooms.
A teaching tool for electronics and microcontroller programming.
A base for more complex projects involving time-based control.

Hardware/Components

The kit includes the following components (in video at 01:21):

AT89C2051 Microcontroller
Two 10kΩ resistors
Two 30pF capacitors
One 100nF capacitor
One 10µF electrolytic capacitor
One 1kΩ resistor array (8 resistors + 1 common pin)
12MHz crystal oscillator
8550 transistor
Two push-button switches
20-pin IC socket
5V buzzer/speaker
Seven-segment display module
Two-pin terminal block
52x42mm PCB

A detailed schematic diagram is available for download at robojax.com (in video at 00:43).

Wiring Guide

The wiring process is extensively illustrated in the video. The schematic diagram (in video at 04:38) shows the connections between the components. A voltage divider is not explicitly used in this project; the resistors are primarily used to limit current to the seven-segment display. The multiplexing technique is used to reduce the number of wires needed to drive the seven-segment display (in video at 05:56). The 12MHz crystal provides the clock signal, which is then divided down to 1Hz by the microcontroller (in video at 06:53).

Live Project/Demonstration

The video demonstrates the assembly process (in video at 07:28) and the functionality of the completed clock (in video at 21:08). The clock is powered by a 5V supply (in video at 21:08). Two buttons are used to set the time and activate the alarm functions (in video at 22:47). The video also shows how to set the two alarms (in video at 23:14).