Pi Pico Digital Clock

This post is still a work in progress and will be updated.

This’s still heavily a work in progress, but I’m posting pictures on this page and will keep it up to date. I’m working on a digital clock, using a Pi Pico, a DS3231 RTC module, and some 74HC595 shift registers for storing / displaying digits.

The goal was to design PCBs for this, but the cost of fabricating the main board was out of budget for this project.


  • Make a digital clock using a Pi Pico. For the LED matrix, I chose to use simpler ICs to make my life more difficult.
  • Code is located @ github.com/richinfante/clock-code/
  • Use CircuitPython (currently halted waiting for rotaryio to be implemented for the pico)
  • Dimmable leds using PWM on the 595’s output-enable pin
  • Rotary switch for dimming, clock setting, menus.


A single digit of the clock, attached to an oscilloscope
Testing a single digit of the clock output
Clock showing time
Front of the clock, showing the current time
Bottom wiring of PCB
Bottom wiring of my PCB, done using 30 gauge solid core wire.
Back wiring of PCB
Back wiring of my PCB, done using 30 gauge solid core wire. All ICs are in sockets for easy replacement.

To be continued!...

under construction

Change Log

  • 2021-03-07 - Initial Revision

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