Keymera: Build Your Own 3D-Printed Keychain Camera with XIAO ESP32S3 Sense
In a world where smartphones handle nearly all of our photography, maker and designer Matej Nahtigal set out to create something different: a tiny camera that’s always with you, simple to use, and fun to build yourself.
Keymera is a fully functional 3D-printed keychain camera powered by the Seeed Studio XIAO ESP32S3 Sense. Small enough to fit on your keyring, Keymera captures photos with a 3MP camera, stores them locally on a microSD card, and lets you browse your gallery over Wi-Fi—without requiring an app, account, or cloud service.
Designed for makers, photographers, and DIY enthusiasts, Keymera combines 3D printing, electronics, and open-source firmware into a compact project that can be built in just a few hours. Currently, the Keymera team is running a Crowdfunding campaign on MakerWorld to bring more Keymera casing designs to the community (the campaign doesn’t involve the electronic parts.). Visit the campaign page to back the project.
Hardware Overview
Keymera keeps the electronics simple while delivering a complete camera experience.
- Seeed Studio XIAO ESP32S3 Sense
- MicroSD Card
- Rechargeable Battery
- Tactile Push Button
- Status LED
- 3D-Printed Enclosure
The project is available in three interchangeable shell designs:
- Rangefinder
- SLR
- Instant
Each design shares the same internal electronics while offering a different visual style.
Thanks to the strong support from the maker community, Keymera has already surpassed its stretch goal and unlocked a fourth shell design: the TLR (Twin-Lens Reflex). Inspired by classic twin-lens cameras, the new design expands the Keymera lineup while maintaining compatibility with the same internal hardware platform.
How It Works
Keymera is designed around a simple interaction model: one button and one LED.
Most of the time, the device remains in deep sleep mode to conserve battery power.
To capture a photo:
- Press the button once.
- Keymera wakes up and captures an image.
- The photo is saved directly to the microSD card.
- The LED flashes to confirm the image has been stored.
- The device automatically returns to sleep.
To browse photos:
- Hold the button for approximately 2.5 seconds.
- Keymera creates its own Wi-Fi hotspot.
- Connect to it using your smartphone.
- Open the gallery directly in your browser.
There’s no companion app to install and no cloud account to manage. Photos stay local and can be downloaded directly from the browser.
One of the most appealing aspects of Keymera is its DIY-friendly assembly process. Builders print the enclosure, connect just four electronic components, upload the firmware through the Arduino IDE, and press-fit everything together. The entire project can typically be completed in about two hours.
Because the firmware source code is included, makers can also modify and extend the camera’s functionality, making Keymera a great platform for experimentation and customization.
Why XIAO ESP32S3 Sense?
For a device designed to fit on a keychain, every millimeter matters.
The XIAO ESP32S3 Sense provided the ideal balance of processing power, wireless connectivity, and camera support in an exceptionally compact package. Its small footprint allowed the entire camera system to fit inside a pocket-sized enclosure while still supporting image capture, local storage, Wi-Fi connectivity, and firmware customization.
By leveraging the XIAO ecosystem, Keymera achieves functionality typically found in much larger devices while remaining lightweight and portable enough for everyday carry.
“The choice of Xiao Seeed Studio was practically a no-brainer. I was so happy when I found it. It’s the smallest possible package which enables the camera to stay compact. But the most important thing is how everything just works, how good the documentation and support is and how easy it was putting it all together. I already have some ideas on what to do next with it!” – Matej Nahtigal
Support the Keymera Campaign
If you’d like to see projects like this continue to grow, consider supporting the Keymera crowdfunding campaign on MakerWorld. Community support has already helped unlock the new TLR shell design, and future stretch goals could bring even more designs and firmware features to all backers. Your support helps bring this unique maker project to a wider audience while expanding what Keymera can become
Interested in building your own Keymera with your own XIAO ESP32-S3 Sense? Visit the campaign page to learn more, access the project files, and support its development.
End Note
Hey community, we’re curating a monthly newsletter centering around the beloved Seeed Studio XIAO. If you want to stay up-to-date with:
🤖️ Cool Projects from the Community to get inspiration and tutorials
📰 Product Updates: firmware update, new product spoiler
📖 Wiki Updates: new wikis + wiki contribution
📣 News: events, contests, and other community stuff
Please click the image below👇 to subscribe now!
About Author
