Here are a few of the many possible variations on the general theme of discrete-logic digital clocks. If you have a few LED displays, counters, drivers, and simple logic, you can probably build a clock. Consult the datasheets of the ICs you choose to use, breadboard everything first, and have fun.
The advent of the ESP32 Wi-Fi development boards allows for an increase in the sophistication of a digital clock. It doesn’t take much imagination to envision a digital clock with a large LCD display to not only show the usual time, date, temperature, and humidity, but to also be able to retrieve things from the Internet like the weather or weather forecast, and stock market reports as well. This seven inch clock also automatically corrects for Daylight Savings Time.
Driving LEDs using the lowest possible pin-count is a common challenge for folks creating projects with microcontrollers. Complementary LED drive, also known as “Charlieplexing”, allows a large number of LEDs to be controlled with a relatively small number of I/O pins. This fun digital LED clock project is a hands-on example of how Charlieplexing can be used to stretch your “pin budget”!
This timely clock project uses CMOS logic and seven-segment displays, which offer the builder many design variations for construction.
This six-digit, beautifully designed timepiece showcases cold war era components — Numitrons instead of Nixie tubes — along with modern LEDs and a Microchip PIC to create not only a useful clock but a great conversation piece as well.
Building digital clocks may not be the sexiest of DIY projects, but it’s still pretty fun. Try this version that utilizes the ESP8266 family of devices which makes incorporating the Network Time Protocol simple.