NOTE: Watchduino is a discontinued project. We are now focusing efforts on Watchduino 2, a follow up revision featuring Bluetooth connectivity.


WatchDuino is an open hardware project that combines inexpensive electronic components and a complex Arduino (C++) code to build a useful and reprogrammable smart watch.

The code and the components have been optimized after a lot of prototypes to provide a rich set of features with a small and cheap battery that can last more than a week without recharging. A lot of electronic and software engineering was required to make this project possible.

Demonstrative video

Watch on Youtube, it's pretty awesome!


  • Time and date (analog and digital output)
  • Alarm / Countdown (with custom music)
  • Games
    • Pong (1 vs com)
    • Snake
  • Rechargeable battery (by USB)
  • Battery meter
  • Low-battery mode (it can last 2 years with 240mAh battery)
  • Built-in screen light
  • Compact design

Main components

  • ATMega 328
  • Crystal oscillator (16Mhz)
  • LiPo battery (240mAh)
  • Nokia 5110 LCD screen

Further reading

Project motivation (local link) - Why we built WatchDuino, what does it offer to the world, and some technical musings.

How to install (local link) - How to set up your system to make it ready to work with WatchDuino.

How to replicate (local link) - Components, libraries, and everything you need to build your own WatchDuino.

How to program (local link) - Hack on WatchDuino's software to make your own apps and customizations.


Copyright 2014 Coconauts

This file is part of WatchDuino.

WatchDuino is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

WatchDuino is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with WatchDuino. If not, see