Solar-Powered PCB Business Card

A business card you can't throw away because it's a circuit board: card-sized, solar-powered, and running a microcontroller off harvested light.

Problem

A paper business card gets recycled in seconds. I wanted something that doubles as a portfolio piece in your hand — a real PCB that demonstrates low-power design and energy harvesting while still fitting in a wallet.

Approach

• Power. A small solar cell feeding an energy-harvesting front end to run a low-power microcontroller without a battery.
• Layout. A card-sized KiCad board treating the silkscreen and copper as design elements, with contact details and links etched into the board itself.
• Firmware. Minimal embedded C to drive a small light/indicator payload within the harvested power budget.

Result

• An in-progress board that merges PCB design, low-power firmware, and a bit of art into something I can actually hand to people.

What's next: finalize the harvesting front end, fabricate the first revision, and tune the firmware to the available power.