Pixie: an Arduino Based NeoPixel Wristwatch




Posted in TechnologyArduino

Introduction: Pixie: an Arduino Based NeoPixel Wristwatch

About: I am a dreamer, maker and an engineer making and sharing interesting projects here at Instructables. Follow me @ instagram: @the_gadget.boy

Ever since the dawn of time, people have begun to dispense time. First was the sundial, later appeared water clock after them was the hourglass. Millennia later was created the first pendulum clock and few centuries later the electronic watch.

Today I'll show you how to make Pixie, a wristwatch that combines both analog and digital clock technology, with the precision of an atomic clock.

PIXIE shows the hours in blue, the minutes in red andthe seconds in green, it also has a flashlight mode that is activated, by capacitive touch switch, for 10 seconds. You may ask why, that's because the LEDs heat-up and they might get damaged, but if you want, you can increase the time at your own risk !

Time format:

Hours: 1 LED = 1 hour

Minuntes: 1 LED = 5 minutes

Seconds: 1 LED = 5 seconds


Step 1: Parts, Materials and Tools for the Project

Step 2: Electrical Design

As you see on the schematics, the RTC module DS1307 is connect to the TWI (I2C) interface of the Arduino board(analog pins 5(SCL) and 4(SDA)) . The NeoPixel ring is connected to pin 3 of the Arduino.

The 1M ohm resistor is connecting pins 10 and 13 together. The "touch" wire is connected to pin 10.

All GND and VSS pins are connected to the Step-Up voltage regulator (not present on any of the schematics above).

Step 3: Building the Watch

First I solder the 1M Ohm resistor to pins 13 and 10, then I solder the 3 wires for the NeoPixel ring and one more for pin 10.

After that I connect the step-up regulator with the RTC's GND and VSS, then I connected SDA, SCL, GND and VSS of the RTC with the Arduino Pro Mini board, again with wires by soldering them.

At the end I hot glue all of the boards together as compact as possible.

Step 4: Enclosure and Design

For enclosure I used a simple cardboard box which I made using a piece of cardboard and some ductape, and a piece of transparent plexiglass, 37 x 37 mm and thick 3 mm, as top.

The size of the box is 37 mm x 37 mm x 15 mm. I also made 2 holes, on the bottom of the box, for the power wires and the "touch" wire.

For the strap I used a piece of filts, long ~ 8 inc and wide 1 inch (~ 20cm x 2,5 cm) and pieces of velcro at the both ends.

Step 5: Software (source Code and Libraries)

Feel free to download the .zip file that contains the whole source code for the watch.

You will also need these libraries:




Wire - its build-in in Arduino IDE


I used Arduino UNO as programming board to upload the sketch to the Pro mini. I suggest you to use that.

Step 6: Showcase



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Please be positive and constructive.




he dude, how to change the TIME in the code to my time???

i see that that part is totaly forgotten to explain!!

Hii, what if I use RTC DS 3231 instead of RTC DS1307?? What changes should I make to the codes and circuit??

1 reply

You have to put the libraries in /Documents/Arduino/libraries. Then you upload the code to the arduino.

There is no problem to use 1/4 watts resistor since the current that goes through is couple mA. :)

Hello! I really want to build this- I was just wondering how you recharge your battery? Thanks!

1 reply

Since the battery is outside the case I simply disconnect it and then I recharge it with my SparkFun Blynk board.

Thank you so mutch,

i got all of it but i just orderd the ws2812 ring,so i must wait a bit.

but o jesss i wil make it. and show it here to you

Greetings from The Netherlands. Simon.

It is possible with this code, using a ring 24 or even 60 LEDs?
Thank you

2 replies

Hi Konstantin! And the LED that displays the seconds flashes? For I have not seen it on video! Thank you

I'm modeling up the components now. Still could use more dimensional data.

2 replies

Whoah ! Nice work jianju, keep goin', by the way if you need more dimensional data about the rest of the components let me know ! :)

Do you have calipers? Actually, I'm certain I will build this project, so I'll go ahead and order the components, take accurate measurements, and post a printable case. I know Fstedie is working on one too, but hey, people will have a choice of design!

WOW! Really cool and inspirational!!! I'll have to think about creating a smaller version (My wrist is very small). The fact that you can use it has a flashlight is well thought. Thanks!

1 reply

this is by far 1 of the most interesting and a REAL DIY IBLE people.

this is a winner.

look at the simplicity, and th use of alrount products.

who cares about the card bord box, thats just the point. thats making it the IBLE of the year for me.

yes it can be made differend, MAKE IT YOURSELF then,

exact. this guy put his time and efford,so dont say this r that can be better.HE KNOWS) and he will. you can bett on that.

Konstatin you are my inspirator from now. i wil PM you friend. verry cool and GOOD, IBLE

Message me with your exact dimensions, I can make you a nice housing on my 3D printer...

1 reply

Hi ! Thanks, will send the exact dimensions as soon as I get home (probably in 1 hour). :)

I found a DS1302 real time clock module. What changes do i have to make in order to use that?