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Business cards are one of those things we all take for granted. They’ve been around forever, usually just a piece of paper with a name and some contact details. But for me, they always felt a little too ordinary. As an Electronics Engineer and a Maker, I couldn’t help but wonder: what if a business card could actually do something?
That thought has been in the back of my mind since 2014, when I first started experimenting with microcontrollers small enough to fit into a credit‑card footprint. I began sketching ideas for a card that could display information on a screen, respond to touch, and maybe even include a few hidden surprises.
Of course, life doesn’t always go in a straight line. Over the years, I had to put the project aside many times, sometimes for months or even years, while work and other responsibilities took over. But every time I came back, I picked it up with fresh eyes, new skills, and new ideas. It became a long‑running personal challenge, something I refused to let go of even when progress was slow.
Fast forward to a month ago, and I finally finished the project: the BZCard. It’s a fully functional interactive electronic business card that features a crisp OLED screen, capacitive touch controls, smart power management, and yes, four retro mini‑games tucked inside as Easter eggs: Snake, Brick Breaker, Tetris, and Death Star.
The idea first came to me in 2014, but I started building the first prototypes in 2016-2017 (you can even find some early videos). Since then, I’ve carried the project forward whenever I had the time, until I finally brought it all together this year.
To show how it works, I uploaded a long demo video on YouTube:
Features- 🖥️ OLED Display: 128×64 pixel screen for Contact Info, Social Media, Games and logo animation.
- ✋ Touch Controls: Five capacitive touch buttons for navigation and interaction.
- 📇 Contact Info Menu: Clean, simple UI for name, email, and phone.
- 🎮 Four Hidden Games: Snake, Brick Breaker, Tetris, Death Star.
- 🔋 Rechargeable Battery: LiPo with USB charging.
- ⚡ Smart Power Management: Automatic sleep, deep sleep, and USB charging screen.
- 🧰 Custom Enclosure: Purpose‑built case to showcase and protect the card.
- 📏 Ultra‑Compact: True credit‑card footprint.
- Memorable first impression: a card that lights up and reacts is hard to forget.
- Personal expression: reflects creativity and a love for building things.
- Playful twist: the games turn a quick interaction into a conversation.
- On power‑up, the card shows a logo screen.
- A menu lets you navigate Contact Info, Social Media, Games (Snake, Brick Breaker, Tetris, Death Star), and Options.
- Capacitive touch inputs control navigation.
- After inactivity, the display sleeps to save power.
- When plugged into USB, a charging animation is displayed.
📸 General Images:
Built around a Microchip ATSAMD21 microcontroller with:
- Capacitive touch sensors (button‑less input)
- OLED display (text, menus, animations)
- Flash storage (settings, scores)
- RTC‑based sleep/wake for power efficiency
Firmware stack (Arduino IDE):
U8g2— OLED renderingFlashStorage— non‑volatile dataRTCZero— timed wake/sleep
The card hides four retro‑style mini‑games as Easter eggs. They aren’t the main purpose of the device, but they make interactions more fun:
- Snake: Grow the snake and avoid its own body. Smooth movement, grid‑aligned collisions.
- Brick Breaker: Destroy bricks with a paddle and ball; adds speed and angle variability for challenge.
- Tetris: Falling tetrominoes with rotation/locking and line clears. Compact UI tuned for 128×64.
- Death Star: A minimalist arcade mini‑game with dodging/targeting mechanics for quick play sessions.
- Auto sleep after ~30s of inactivity
- Deep sleep after ~120s
- USB detection + charging screen
- Wake via touch on any button and on power button after deep sleep
To make the project easier to handle and display, I redesigned and 3D printed a custom card enclosure. While the electronics are genuinely credit‑card sized, the enclosure gives it a more polished feel, like a tiny handheld, and protects it when showing it to others. It also makes it easy to leave the BZCard on a desk or shelf as a conversation piece.
📸 Enclosure Images:
Back when I first started experimenting with the idea of a credit-card sized device, I came across the original Arduboy prototype. It amazed me that such a small device could run real games and feel so polished.
While the BZCard isn’t meant to be a game console, that early glimpse of Arduboy definitely left an impression. It encouraged me to think seriously about how the same form factor could be used differently, in my case, as a business card that displays contact information and also hides a few fun mini-games inside.
ConclusionLooking back, the BZCard is more than an electronic gadget. It represents years of persistence and curiosity, an idea that started taking form in 2017, paused and resumed many times, and finally came together a month ago. Finishing it was a personal milestone, not because it’s grand or complicated, but because it’s proof that some ideas are worth carrying forward until they exist in the real world.
What makes this card special to me isn’t just the components or the code. It’s what it stands for: that engineering can be expressive, that creativity can live in small objects, and that even something as ordinary as a business card can become a playful canvas. The custom enclosure completes that feeling, it’s not something that has to live in a wallet; it stands on its own, ready to be picked up, explored, and enjoyed.
When I hand someone the BZCard, I’m not just sharing contact details. I’m sharing a small piece of my journey, the stubbornness to see an idea through, the joy of building, and the belief that tiny things can still make people smile.
Credits- Concept & Development: Diego Galue
- Timeline: Idea in 2014, started in 2017, completed in 2025
- Status: Personal project
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