Introduction: Pixie: an Arduino Based NeoPixel Wristwatch

Picture of Pixie: an Arduino Based NeoPixel Wristwatch

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

Picture of Parts, Materials and Tools for the Project

Step 2: Electrical Design

Picture of 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

Picture of 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

Picture of 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)

Picture of 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

Picture of Showcase


chrisp15 made it! (author)2017-11-06

I've been trying this for weeks, but after I breadboard it and try the code the flashlight will work, but the watch does not. All it does is keep one bright pixel on permanently. I am using a slightly different DS1307 RTC but I cant see why that would affect this?

Any ideas?

I have the same problem with the build too.

Thhe Randomatstar (author)2017-12-03

Where's the code

WannaDuino (author)2017-10-09

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

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

Sounder R (author)2016-12-20

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

Konstantin Dimitrov (author)2016-11-13

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. :)

holographicleah (author)2016-11-08

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

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

WannaDuino (author)2016-09-26

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.

dancopy (author)2016-09-25

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

Yes, it is possible !

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

jianju (author)2016-09-25

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

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!

Stéphane-GabrielM (author)2016-09-25

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!

Thanks, Stéphane-GabrielM ! If you need help about making smaller watch let me know ! Thanks again !

WannaDuino (author)2016-09-25

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

fstedie (author)2016-09-25

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

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

charlie-lee-rhee (author)2016-09-19

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

Hi ! Excuse me for the late answer, in order to use DS1302 I have to rewrite the whole sketch so it can work. I will upload it as late as Tuesday 27th.

MarcoG6 (author)2016-09-16

you could probably skip the boost converter and skip the arduino voltage regulator to save on power becuse the ardiuno can handle the max 4.2 volts from the battery just fine i have found, also the neo pixel ring can run on less voltage as long as you dont turn on to many of them at once. I was working on a project like this a while ago I ended up sanding down a 3v pro mini to fit inside the middle of the ring, and wiring the battery straight into the vcc of the arduino, and not useing a RTC as i found that as long as its within 5 min it ok, and I got away with useing a 400mah battery that would last 3 days. but iam horrible at coding so i bet you could optimize that code a bunch becuse I couldn't figure out how to get the time to display when you hit a button so I just had the button connect the neopixel vcc.

I see, yes its possible but I decided use RTC cause it will keep time even when the whole watch is powered down. I was thinking to use one ESP8266 to make better watch, I would program it to get time from the net and also to sleep when I don't need it and when I need to know what time it is, I press button to wake it up. The whole watch would be powered directly from the battery.

If I had used another RTC like DS3231 I would directly powered from the battery cause DS3231 uses 3v to run.

By the way the Pro mini I use can run on both 3.3v and 5v.

yes but if you skip the power regulator the pro mini you can power the chip directly, which saves power, also a esp8266 would be awesome for this.

F1awless (author)2016-09-16

Hey, I am pretty new to Arduino and I really want to make this. For the wires, is there a specific brand that you use or would any electrical wire work? Could you provide a link if possible? Thank you

I usually go to the nearest electronic store and buy USB cables, they have 4 colored wires(red, black, green and white) that are perfect for small electronics like my watch.

JunezRiyaz (author)2016-09-15

Cool work. Awesome

Thank you !

turbiny (author)2016-09-14

How long will it work on one charge?

As we know, batteries have capacity and Capacity = Current * Time (C = I*t).

In my case PIXIE in "watch mode" consumes 60 mAh and my battery has 650mAh capacity, which means that the battery will hold up to ~ 13 hours.

About This Instructable



Bio: I am a dreamer, maker and an engineer making and sharing interesting projects here at Instructables. Follow me @ instagram: @the_gadget.boy
More by Konstantin Dimitrov:Arduino/Genuino 101 BLE Thermometer With TMP102 and BlynkPixie: An Arduino Based NeoPixel WristwatchTurn Your Old 2.5'' Or 3.5'' Hard Drive Into Portable/External
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