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You can build a DIY smartwatch by pairing a compatible microcontroller and display with firmware designed for that hardware, then adding input, battery power, and an enclosure in stages. The simplest prototype can show the time and respond to a button; a more capable build can add touch, connectivity, notifications, or sensors. The key is to choose the board and its software together—firmware for one watch board is not automatically compatible with another.
Choose the kind of smartwatch you want to build
“Smartwatch” can mean a programmable clock you wear or a connected device with sensors and companion software. Set a modest first goal: a clock and one input action. Add weather, phone notifications, activity tracking, or other sensors only when your chosen hardware and software support them.
These documented projects illustrate the range: a small ESP32-C6 build has clock, weather, and timer screens, while an ESP32-S3 project targets a more feature-rich touch watch. Those are project-documented capabilities, not guarantees that every board or software version will deliver the same functions.
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Pick a build path before buying parts
| Build path | What it offers | Effort and trade-offs |
|---|---|---|
| ESP32-S3 integrated board with existing firmware | The firmware targets the Waveshare ESP32-S3-Touch-AMOLED-1.8, documented with an ESP32-S3R8, 1.8-inch 368 × 448 AMOLED touchscreen, power management and LiPo connector, motion sensor, RTC, audio codec, microSD, Wi-Fi, and Bluetooth LE. The project documents touch, notifications through Gadgetbridge, activity and sleep features, alarms, and other applications. Project repository | The most direct route to a documented, feature-rich starting point, provided you use the exact target board and follow its current setup requirements. Its feature list is not an independent performance test. |
| ESP32-C6 with OLED | Soldered’s NULA Mini ESP32-C6 project uses a 0.96-inch 128 × 64 SSD1306 OLED and momentary button. Its screens cover clock, weather, timer, and an animated home screen. Project documentation | A compact learning prototype with documented Arduino setup, wiring, Wi-Fi configuration, upload, and serial-monitor diagnostics. A compatible small LiPo battery and charger, plus a printed enclosure or strap, are optional for wearable use. |
| Custom ESP32 wearable | Espressif’s MutantW profile describes a 44 mm watch using an ESP32-WROOM, custom PCB, 1.7-inch 240 × 280 LCD, buttons, vibration motor, Wi-Fi, Bluetooth, and over-the-air programming. MutantW profile | More room to control the form factor, but it is an adaptation project involving hardware and enclosure work—not a guaranteed beginner parts list. |
| RP2040 watch-board adaptation | Raspberry Pi’s 2023 article describes a watch board with an RP2040 and 1.28-inch TFT. The makers investigated its display and controls, added a rechargeable LiPo, and designed a printable case. Raspberry Pi article | Expect reverse engineering: the board lacked documentation and a battery, making it less straightforward than a maintained, documented target. |
| OpenTimeWatch platform | The open hardware and software project supports boards including LILYGO TQT Pro and lists watch faces, games, a torch, motion sensors, Wi-Fi time setting, speaker, battery voltage, and charging. OpenTimeWatch project | Offers a platform for adaptation, including a separate custom smartwatch PCB. Its documentation says the activity view is a dummy and is not functionally implemented. |
For a first build, favor a board with firmware and setup instructions that name the exact hardware. The ESP32-S3 target is the clearest route to the documented feature-rich firmware; the ESP32-C6/OLED approach keeps the prototype small and focused. Custom-PCB and undocumented-board routes offer more adaptation work and less plug-and-play support.
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Gather compatible parts and check the interfaces
For the ESP32-C6 prototype, the documented core is a compatible ESP32-C6 board, 0.96-inch SSD1306 OLED, and momentary button. USB-C provides programming and power during development. Wearable use adds a compatible LiPo battery and charger, and an enclosure or strap.
For either path, use the selected project’s current documentation as the bill of materials. Before ordering or wiring, confirm:
- The exact board model and firmware-supported board profile.
- The display type, interface, and pin mapping; two displays of similar size are not necessarily interchangeable.
- The button GPIO and any other input wiring.
- Required libraries, versions, and board settings.
- How the board handles battery input, charging, and power management.
The ESP32-S3 firmware repository documents Arduino IDE 2 setup, Espressif ESP32 board support, required libraries, board settings, and upload steps. The Soldered project documents Arduino setup, board and library installation, wiring, and Wi-Fi configuration. Follow the instructions for your chosen build rather than mixing pin assignments or libraries across projects.
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- 【Beginner-Friendly DIY Electronics Kit】This soldering kit contains through-hole components designed for easy soldering practice, suitable for those new to electronics assembly. The included parts can be assembled using basic soldering equipment.
- 【Automatic Power Conservation Feature】The device includes a power management function that activates after a short period of non-use. The display can be quickly restored with a simple button press.
- 【Straightforward Time Adjustment Controls】Two clearly labeled buttons allow for simple time setting adjustments. One button modifies hours while the other adjusts minutes, with an option for faster setting changes when needed.
- 【Clear View Enclosure Design】The assembled project features a transparent housing that allows observation of the internal components. The durable construction maintains functionality while providing visibility of the circuitry.
- 【Comprehensive Assembly Instructions】The package includes detailed visual guides and circuit diagrams to assist with the building process. Helpful reference materials are provided to support the assembly experience.
Bring up the watch on USB before making it wearable
- Install the documented development setup. Follow the selected project’s instructions for the IDE, board support package, libraries, and board settings.
- Connect the display and input. Check the wiring and pin mapping against that project’s diagram or configuration.
- Upload the example or project firmware over USB. Use the upload method and target board specified in the documentation.
- Confirm the display and button work. Check that the screen renders and the input triggers the expected action.
- Use serial diagnostics when available. The Soldered project documents checking the serial monitor after upload, which can help identify setup or connection problems.
Do not add a battery or close the case until the basic electronics work on USB. Keeping the prototype accessible makes wiring and firmware problems easier to isolate.
Add functions one at a time
Start with a clock and one control action, then add only features supported by your board and software. The ESP32-C6 project documents clock, weather, and timer screens. The ESP32-S3 firmware lists a broader set of capabilities, including touch interaction, notifications through Gadgetbridge, activity and sleep features, and alarms. Companion-app support and feature availability depend on the project and version; treat documentation as a feature list, not proof of results on your particular build.
OpenTimeWatch is another option for adapting an open platform, but its project page explicitly identifies the activity view as a nonfunctional dummy. Do not assume a feature is implemented merely because it appears in a project menu or description.
Rank #3
- DIY electronic watch kit: The watch uses plug-in components to reduce soldering difficulty and is suitable for beginners.
- Silicon watch band:The blue silicone strap is wear-resistant, providing a comfortable experience for both sports and leisure.The length of the watch strap is 90+120mm, plus 50mm for the watch, the overall length of the watch is 260mm.
- Watch functions: the watch with transparent shell, red LED 4 digital tube,and 2 set buttons S1,S2.Press any button to display the time, which will automatically turn off after 10 seconds. Keep holding down S1 and adjust the minutes. Keep holding down S2 and adjust the hours. By short circuiting the solder joints on the back, a 24-hour display can be set.
- Watch size: 50x45x16mm. digital tube display size: 0.28 inch.
- Tutorials: Package includes paper instructions and web page with step-by-step soldering pictures and videos. Low soldering difficulty by using direct plug components.widely used in schools to help students learn basic mechanical and electronic skills.Through the analysis of the circuit, understand the working principle of the circuit, learn to train electronic skills, welding training.
Integrate battery power safely and deliberately
LiPo batteries, connectors, and charging arrangements are not universal. The Soldered project identifies a small LiPo battery and charger as optional parts; that does not establish compatibility with every ESP32-C6 board. Select a battery and charger that match your exact board and follow their documentation.
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Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →The Raspberry Pi adaptation reports that its board had an unusual battery connector and that the makers resorted to direct soldering. That is a project-specific account, not a general wiring recommendation. Do not copy it without confirming the electrical and mechanical requirements for your own hardware.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Fit the enclosure around the working electronics
Once the display, controls, and power setup work, design or adapt the case around the actual components. The Soldered project treats a printed enclosure or strap as optional; the MutantW and Raspberry Pi projects also document printed case parts. Leave room for:
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- 【Installation Guide】Before replacing the screen, be sure to disconnect the watch battery. You can find videos on YouTube about the installation of this model of screen and install it carefully, but I strongly recommend that you go to a professional watch repair shop to install the screen.
- 【After Sale Service】:Please check if the screen is damaged or broken after receiving the package,If you receive a product that is not working, please don't worry, we will provide you a new replacement or provide you a satisfied solution,please contact me in a timely manner.
- A clear view of the display and access to buttons.
- The actual battery shape, board connectors, and charging access.
- Antenna operation; avoid enclosing or obstructing the antenna without checking the board guidance.
- Assembly tolerances, cables, and the way the watch sits on the wrist.
Prototype the fit before final assembly. A case that looks right in a drawing may interfere with a button, charging cable, antenna, or battery once printed and assembled.
Test the functions and limits of your particular build
Before relying on the watch, check the use cases you actually implemented:
- Does the clock display and update as expected? If you enabled time synchronization, confirm it works over the chosen connection.
- Do buttons or touch controls respond consistently?
- Is the display readable in the conditions where you plan to use it?
- Do Wi-Fi, Bluetooth, or companion-app features work with your selected board and software version?
- Does the battery charge through the intended circuit, and does the assembled case fit without stressing the cell or wiring?
The cited project descriptions do not establish a guaranteed battery runtime, water resistance, medical-grade sensing, or compatibility with every phone. Verify those properties for the exact hardware, software, and enclosure rather than assuming them from the word “smartwatch.”
What a DIY smartwatch project can—and cannot—promise
A smartwatch is a platform-and-software project, not just a board with a screen. Existing firmware can save substantial software work, while custom hardware gives you more control at the cost of integration effort. The project documentation frames OpenTimeWatch’s aim as “complete flexibility and control over the technology you wear.” What you actually get depends on the supported board, implemented software features, compatible companion tools, and the quality of your assembly.
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