A very specific request!
The is a legendary open-source, Arduino-based Morse code keyer developed by Anthony Good (K3NG). It provides features that easily rival high-end commercial hardware.
The K3NG keyer is a testament to what an open-source community can achieve. The base software is a masterpiece of engineering, but its true beauty is in the countless "repacks" that have sprung from it. Whether you are looking to build a tiny, portable keyer for field days, a feature-packed station controller for your home shack, or simply a fun weekend project to learn about Arduino programming, there is a K3NG "repack" with a schematic that is perfect for you.
Directly connecting an Arduino pin to a vintage or even modern transceiver can destroy the microcontroller due to high voltages or reverse currents. This repack utilizes optocouplers for total electrical isolation.
For the ultimate standalone experience, adding an LCD or OLED display tracks your WPM, memory slots, and sent text. Highly recommended to save pins. VCC to 5V GND to GND SDA to Arduino A4 (on Nano/Uno) or Pin 20 (on Mega) SCL to Arduino A5 (on Nano/Uno) or Pin 21 (on Mega) 3. Pin Mapping Reference Guide
A thoughtful, well-executed liberates that potential. Whether you download one from a GitHub fork or patiently redraw your own, using a repack means spending less time guessing wiring and more time sending perfect CW.
Overlooked in many fragmented schematics, a repack includes:
What exactly should you expect from a high-quality repack? Let’s break it down by functional block.
Dual paddles, speed pot, basic command buttons, simple piezo sidetone, basic WinKey emulation. Full-featured desktop stations, contest logging
If you want a more streamlined building experience, consider searching for "nanokeyer" projects or dedicated PCB providers that have already designed PCBs specifically for the K3NG codebase, as they often simplify the wiring shown in the base schematics PDF 1.2.5. If you'd like, I can: Recommend specific, high-quality Arduino Nano clones Help you find a pre-made PCB layout or kit