The setup is simple but effective. A Morse code ... keyer. This audio is passed into the headset port of a Baofeng handheld transmitter. A toggle switch is wired up to the Push-To-Transmit circuit ...

It is reasonably easy to make a microcontroller spit out some Morse code. What makes [pavlin ... If you want a much larger Arduino-based keyer, we’ve seen those, too.