Summary： Digital clock has an analog-style LED face with digital circuitry. It runs on an USB-A phone charger and uses three AAA batteries for backup.
My shared clock project is now available on PCBWay. This is the second version of my LED ring clock, which uses two LED rings: the inner ring shows the hours and half hours, and the outer ring shows the minutes. There is no second-hand, giving the display a clean, simple look. I ordered the first version on February 2nd, 2026, with five PCBs made and one board assembled. Since PCBWay did not accept PayPal at the time, I paid through Payoneer. That version worked, but it revealed three issues: the half-hour LEDs did not advance correctly, the power connector was USB-A instead of USB-C, and the minute and hour/half-hour counters could sometimes start out of sync. I fixed these by updating the diode placement and connection, replacing the connector with a USB-C pigtail, and resolving the sync issue by disconnecting one battery and restarting the clock. The completed first version is now on my wall and keeping accurate time, but it was never posted as a shared project.
In this updated version, I incorporated those improvements directly into the design. The schematic and PCB layout now include the diode correction, the board uses a USB-C connector soldered directly to the PCB, and a reset circuit sets the clock to 12:00 at power-up. To verify the USB-C connector before using it in the full clock design, I also created a small test board with a USB-C connector, a resistor, and an LED, and had one sample assembled.
For the current version, I placed the order on May 9th, and the assembled clock board along with four bare PCBs arrived by DHL on June 9th. This time, I was able to pay by MasterCard instead of Payoneer or PayPal.
The clock is set with two push buttons: one for slow minute adjustment and one for faster setting, including the hours. A third button synchronizes the minutes by resetting the internal seconds counter to zero. To use it, set the clock one minute ahead of the current time, press the button, and then press it again when the actual time reaches the exact minute. I use the National Institute of Standards and Technology | NIST as an accurate time source.
Timekeeping is based on a 32,768 Hz crystal and two CD4060BE 14-stage ripple counters, which generate a one-minute clock pulse.
Although similar LED clock projects can be found online, this version takes a discrete-logic approach and does not use a microcontroller. The circuit is built around two CD4060BE ICs, two CD4069UB ICs, and four CD4017BE ICs. I had wanted to build this type of clock for a long time and finally began the project last year. Before starting this design, I ordered PCBs for another project, the 24-Hour Digital Clock https://www.pcbway.com/project/shareproject/24_Hour_Digital_Clock_77a8b997.html, on September 8th, 2026. This clock borrows part of its timekeeping circuit from that design. The assembled 24-Hour Digital Clock now sits in a small alcove in my living room, while the original version of my clock hangs on the living room wall. The new clock is currently in a drawer, running only on batteries for testing. It has run for more than 72 hours, the LEDs remain bright, and the time is still accurate. I plan to give it to my sister as a birthday gift.
You can view the shared PCBWay project here: https://www.pcbway.com/project/shareproject/W896177ASE35_Clock_kicad_pcb_1eeb7dd8.html
