: For those using an Arduino Mega, the UN7FGO K3NG Shield is a highly recommended PCB design that breaks out all major features. Configuration & Setup
Safely interface Arduino’s 5V logic to the transceiver’s key input (which may be 0–12V, high impedance, or require current sinking). k3ng keyer schematic
"I added three," Elias said, pointing to three tactile switches. "One for 'CQ', one for my call sign, and one for '5NN TU'." : For those using an Arduino Mega, the