Single & Dual Digit (0–9 / 00–99) | ESP32

Mechanical 7-Segment Countdown Clock is an original 3D-printed project that uses micro servos to create a fully mechanical numerical display.

This project includes two different versions, both available in the same download:

Single Digit – 0 to 9

A compact version with 7 independently moving segments, powered by 7 MF90 micro servos. It can display numbers from 0 to 9 and perform countdowns.

Dual Digit – 00 to 99

The complete version, featuring 14 independently moving segments controlled by 14 MF90 micro servos. It can display any number from 00 to 99 and perform mechanical countdowns.

Both versions use an ESP32 and a PCA9685 servo controller.

Features

• Countdown timer with adjustable speed.
• Interactive rotary dial, optimised for smartphones.
• Wi-Fi control without additional apps.
• Random dance animations.
• Individual servo calibration.
• Saved ON/OFF positions for every segment.
• Calibration backup and restore.
• All ON and All OFF modes.
• English and Spanish web interfaces.

3D Printing

The original design was created specifically for this project and printed using an Anycubic Kobra X with Anycubic PETG-CF filament.

Both 3MF model variants can be downloaded from this project.

Separate ESP32 firmware files are provided for the 7-servo and 14-servo versions, together with a wiring diagram reference, component list and setup instructions.

Components

ComponentSingle Digit (0–9)Dual Digit (00–99)MF90 micro servos714ESP32 development board11PCA9685 PWM controller11External regulated 5 V power supply113D-printed partsSingle-digit 3MFDual-digit 3MFServo horns and mounting screwsAs requiredAs requiredWiring and connectorsAs requiredAs required