Arduino Smart Watch

A very basic yet expandable smart watch based upon Adafruit's 5v Pro Trinket board

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My "Arduino smart watch" project is a simple yet very capable Arduino based platform. The current version of the watch is functioning correctly and is at a size that I could confidently wear (1.4cm in width).
The current version is based upon adafruit's pro trinket board (5v) which is both a great size and capable of running my program. The watch is powered by a 500mah lipo batter (located on the wrist band as to remove thickness) and the voltage is boosted using Adafruit's basic 500 power boost. The program is very basic at the moment (i am hoping to add temperature and possibly connectivity with my phone in the future) and only projects time, AM and PM and what time my next period begins (based off my school time-table).
The case was printed using PLA plastic on my Printbot simple metal and designed in 123d Autodesk design. The main feature of the watch is its ability to be programmable and its ability to expand and act as a useful and reliable platform.

The Challenge the project addresses:
Smart watch accessibility and affordability.

This project aims to create a simple to use fully expandable and open source smart watch platform. 

How the project will alleviate or solve the problem:
By providing an open platform for makers to replicate my design smart watch technology should become more common and accessible. The simple approach to my design should also enable younger makers to get involved, possibly using my platform as an education platform. 

How the Project will be world changing:
By providing an open source and accessible platform the possibilities are endless. Smart watch technology can be utilised in various different areas including;

  • Biomedical technologies (heart rate, fitness etc.).
  • IoT technologies 
  • Business (emails, appointments etc.)

Libraries used:

FTOLED (Oled screen driver)

Arduinosmartwatch battery cover.stl

Due to the lack of space in the watch I had to place the battery on the wrist band. This is the 3D print file for the battery cover.

Standard Tesselated Geometry - 631.85 kB - 09/13/2017 at 00:21


Arudino_Smartwatch V1.2 Enlarged.stl

3D STL print file for the smart watch case.

Standard Tesselated Geometry - 520.06 kB - 09/13/2017 at 00:21



This is the first revision of the code, it doesn't use an RTC module for timing and merely relies on the micro-controller alone. (it is a pretty primitive approach)

ino - 4.09 kB - 09/13/2017 at 00:16



Freetronics OLED library license

license - 34.32 kB - 09/12/2017 at 04:10


  • 1 × Freetronics 128X128 OLED screen
  • 1 × Adafruit 500mah Lipo
  • 1 × Adafruit 5v pro trinket Arduino board
  • 1 × Adafruit Basic 500 5V power boost

  • My smart watch journey continues

    Austin Marandos04/21/2018 at 15:33 0 comments

    Hi guys,

    This project has been very inactive in the past few years, but fear not! My journey in smart watch electronics has been ongoing throughout the past 3 years. 

    Over the past few years I have been developing a smart watch designed for anxiety and panic attack sufferers, using the experiences from this smart watch project I have been working very hard on this new project.

    I am happy to finally make my new smart watch completely open source and I am entering into the 2018 Hackaday prize. Please visit my new project page and tell me what you think! Maybe even make one for yourself!



  • Project re-design

    Austin Marandos09/12/2017 at 10:33 0 comments

    My original smart watch design was really primitive, it relied solely on the micro-controller for timing meaning that when it turned off the time was lost.

    My new approach follows the traditional method of electronic time keeping, using an RTC (real time clock). I have decided to use the DS1307 module since it operates at 5 volts. 

    I will also be working on creating a menu and settings page so that the user can change the time more easily. 

    Stay tuned!

  • Rebuild time

    Austin Marandos01/13/2016 at 12:45 0 comments

    After putting this project away for some time (to make room for another project soon to be released on my profile) I have decided to rebuild/resolder the whole watch. The 3D printed case and band will stay put however the circuitry will be re soldered and cleaned out. The reasons behind this is due to my lazy and terrible wiring (as per the images) and because if I am going to be wearing the watch I want it to be 100% safe and functional (Don't want any short circuits while I'm wearing it at school). I also believe that rebuilding the watch will increase its longevity. I have decided not to create a custom PCB due to time/money and I don't want the waste the components I currently have. I will also be creating a more sophisticated GUI for the watch since it's current version is very basic (which isnt always a bad thing...). Stay tuned for more on the watch, and check out my profile in the upcoming weeks for a new project (Star Wars themed) :)

  • Buttons and wires....

    Austin Marandos12/05/2015 at 05:00 0 comments

    The much needed push buttons are now installed, meaning I can now change the time without having to change the code. The new buttons will also be helpful for my new UI. I am hoping to create a user interface with a menu (much like typical smart watches) instead of just the basic time and event updater.

    And of-course with every project the wires are a pain... Next time i make a watch I'm going straight to Eagle PCB creator...

  • Inside view

    Austin Marandos12/05/2015 at 00:40 0 comments

    Here is a photo of the inside view of the watch. The Pro trinket is located on the upper end, and the power boost is on the lower end. Due to the fact that my watch is not made using a custom circuit board and utilizes only "Off the shelf components" there is not much room for expansion. I hope to install my TMP36 temperature sensor in the near future and make some software changes. Sorry for the inactivity, stay tuned for more updates in the upcoming weeks

View all 5 project logs

  • 1
    3D printing the case

    Start by downloading the 3D print files in the 'files' section.

    Depending on your printer the settings will vary however i would recommend 

    -100% Fill density

    -Supporting structures are a must

    - PLA or ABS plastic is fine.

    The print should take around an hour and a half (depending on the speed of your printer). The geometric shape is relatively simple so you can print at a normal speed.

    If you do not own a 3D printer, 3D hubs ( is a great site, it allows you to 3D print any file from community based printers around your area.

  • 2
    Purchasing electronics

    You will need the following:

    Version 1: (without RTC)

    - Freetronics OLED 128x128 screen (purchased from:

    -Adafruit pro trinket 5V (

    -Adafruit 3.7v 500Mah LiPo (

    - Adafruit 5V boost circuit (

    Version 2 (with RTC)

    - Sparkfun DS1307 (for 5volts) (

    - or alternatively for a 3.3v system you can use the DS3231 RTC (

  • 3
    Circuit Construction

    Create the circuit as per the diagram:

    Please note: The OLED screen in the circuit diagram above is incorrect, unfortunately there was no Fritzing file for the freetronics OLED. To attach the OLED screen please follow the very detailed guide on the freetronics website: ( 

    Pinout for OLED screen:


    For the buttons i originally used resistors and passed 5 volts through the button with a 10k ohm resistor to prevent any damage. This is a complete waste of space. You can easily use the buttons without resistors by utilising the 'INPUT_PULLUP' state in the Void setup() of the code. 

    You will need to swap your buttonstates if you do it this way:


    instead of if(buttonstate == HIGH)  {}

    change to if(buttonstate == LOW) {}

View all 5 instructions

Enjoy this project?



Samuel Comeau wrote 01/19/2018 at 05:03 point

So I've been working on a similar project. I recommend checking out crystalfontz. They have a color lcd for $5 that will take your display current from 14ma to 1mA. They even have an arduino library (havent tryed it yet, getting my parts this week) The issue you would run into is you would need to switch to 3.3V (with and buck or ldo regulator off the lipo). 

  Are you sure? yes | no

pdrift86 wrote 12/02/2015 at 13:49 point

Hi i like your project. Any updates on the watch?

  Are you sure? yes | no

Austin Marandos wrote 12/03/2015 at 02:47 point

Hi, Now that I am on holidays i will be making some updates to the watch, stay tuned!

  Are you sure? yes | no

LC wrote 11/19/2015 at 16:02 point

bluetooth or WiFi?

  Are you sure? yes | no

Austin Marandos wrote 11/23/2015 at 10:03 point

none at the moment, I will hopefully be adding bluetooth in the future

  Are you sure? yes | no

Ben Hur Goncalves wrote 09/20/2015 at 18:46 point

Great! How much time does the battery last?

  Are you sure? yes | no

Austin Marandos wrote 09/21/2015 at 07:55 point

Hey Ben, I haven't tested it for that long to know, I will let you know once I have worn it for long enough! :) . I believe however that theoretically it should last around 7-9 hours.

  Are you sure? yes | no

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