Make: Projects

Build Your Own Pebble: The DIY Smartwatch

Build a low power watch from off-the-shelf components and breakout boards

  • By
  • Time Required: 20-40 hours
  • Difficulty: Difficult

os_smartwatch_v2

  • Time required: 20–40
  • Cost: $75–$125

My Open-Source SmartWatch combines readily available breakout boards, careful soldering, and a 3D-printed frame to make a one-of-a-kind timepiece that displays notifications from your smartphone and is easily customizable in function and appearance.

The watch design is straightforward, consisting of four major sections: a battery charging circuit, vibrating motor for silent alerts, programmable Arduino-compatible core with power regulation and Bluetooth LE, and an OLED display with pushbuttons.

Breadboarding the project is a snap. Wiring it into a small enclosure meant for the wrist is quite another matter. Break out your fine-point soldering iron and follow the complete instructions at oswatch.org.

schematic_battery

Battery Charging

A 3.7V 500mAh LiPo battery is wired to a JST connector and a two-position switch. Switched to the right, the circuit is in battery mode. Switched left, it’s ready for LiPo charging via the JST connector.

schematic_microduino_program

Programmable Core

Within the 3D-printed frame an 8MHz Microduino microcontroller is connected to a programming port, a Bluetooth Low Energy board for communicating with your smartphone or other devices, and a voltage regulating circuit.

schematic_motor

Vibrating Motor

The simple vibrator circuit consists of a diode, 1K and 33Ω resistors, capacitor, NPN transistor, and motor. The circuit is then connected to the Microduino to buzz your wrist when new calls or alerts come in.

schematic_buttons

Pushbuttons and OLED Display

Four momentary pushbutton switches are wired to three pull-up resistors internal to the Microduino and a single external 10K pull-down resistor.

schematic_screen_leds

An OLED screen and two small LEDs are wired directly to seven of the digital pins on the Microduino to display time, text, alerts, and more.

complete

Jonathan Cook

Jonathan Cook

Jonathan Cook is a product manager by day, a hacker by night, and an artist when he has the time. He has been merging his love of technology & creativity since he could pick up a pencil and a soldering iron.


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  • dwest

    insert edit here because someone thinks i’m a “troll.”

    • Marian Mahjoubi Assil

      What does that have to do with the Hardware? Only the demo-App is for iOS, you can make your own for Android.

      • dwest

        yes, i realize this now. forgive me for not being up there with the monolithic intelligences. the example code being in iOS doesn’t really help if you’re not as familiar with cross-platform programming. i know “some” Android stuff and zero iOS.

    • tripside

      It’s an open source watch. You can program it with whatever code you want. There is nothing about this watch that makes it only work with one type of mobile platform or another. That’s a fact.

      Maybe you’re just trolling, though. In that case, shame on you.

      • dwest

        forgive my ignorance oh wise and all-knowing one. i wasn’t “trolling” as you suggest. after searching and chasing down all the parts the only example code i came across was for the iOS.

        • tripside

          Forgive me for expecting you to have some knowledge of the components you outright rejected in your comment. I apologize for the accusation of trolling. When trolling, platform fanbois tend to use the type of dismissive language that you did, hence my accusation. I now understand that was erroneous, and for that I apologize.

          This open source watch is powered by a Microduino board containing an Atmel ATmega1284P, a microcontroller with an integrated 8-bit AVR CPU that is programmable with AVR C. It is compatible with the Arduino platform for which there is a plethora of code out there. You can integrate this watch with any platform you want it to as long as you’re willing to write the code for any functionality that does not exist. AVR is not tied to either the iOS or the Android ecosystems.

  • LIES! The subtitle indicates: “off-the-shelf components” But you must custom make the casing. Which would require many more tools than I have available.

  • p nguyen

    Great article. I won’t build a Pebble but other devices you can derive from this Make recipe. How about a Sp02 device for the smoker so that any time they have difficulty to breath, the can look at this wrist device to control their breathing method ?

  • dwest

    please post some example code for Android? thank you.

  • Oh man. I just made my own watch, and I was pretty proud of it. Then I see this one.

    • Christopher Bulat

      How exactly did you do this?? Please elaborate.

  • Chris Stai

    hey people good job there but i have one question; where can i find the code for this?

  • rroels

    What kind of battery life does the suggested 500mAh battery provide? I guess it depend on how much the bluetooth connection, LCD and leds are used but I’m curious what I can expect from this setup.

  • c.

    is the link for the voltage regulator on your site perhaps pointing to the wrong product?

    It’s currently calling for an NCP1402 step-up regulator, which I believe takes input voltages *lower* than 3.3 and steps them up to 3.3: https://www.pololu.com/product/2114

    If fed a higher voltage, like the 3.7v (really up to 4.2v) battery used here, I think it would just pass it through to the device?

  • Thank you very much for the tutorial jonathan. Worth sharing. (Y)

    Robin.

  • Valmach

    Just wondering if we could get a price breakdown on all parts.. Seems a bit expensive..

  • Mamun

    What is the width and length of the watch, dimensions?