Over the years, I’ve worked on countless electronics projects, often making my PCBs by hand and prototyping with breadboards and Dupont wires. One of the biggest headaches I faced was dealing with unreliable connections—whether it was sketchy PCBs or those pesky Dupont connectors that loosen after a few uses, causing intermittent issues. Living by the ocean added another challenge: corrosion, which only made things worse.

      A few years ago, I noticed that many of my projects shared similar requirements. That’s when I decided to design a small PCB specifically for my Wemos D1 Mini projects. This board had several advantages: screw terminals for secure connections, a direct plug-in for an OLED display, two push buttons, an IR receiver, and support for a 2-channel 5V relay module. With this setup and the right firmware, I could build a variety of devices on the same board.

  The Firefly Mini is a compact, reliable, and incredibly useful board that can simplify your projects and eliminate the frustrations of bad connections. I hope you find it as helpful as I have!