: Wire a PS/2 data line and clock line to digital pins with 4.7k-ohm pull-up resistors to 5V, allowing you to type Morse code directly from a keyboard.
Elias rummaged through the drawer, pushing aside ancient crystals and strange connectors, until his fingers brushed a small, blue circuit board. An Arduino Nano, still in its anti-static bag.
A simple piezo buzzer or a small speaker driven through a capacitor and a current-limiting resistor. Popular PCB Implementations
: Connects to Arduino Digital Pin 11 through a 4.7k ohm resistor (limits current). k3ng keyer schematic
Connect to digital pins (commonly pins 2 and 5 for left/right), pulled high by the Arduino's internal resistors. Transmitter Keying:
A digital output pin (e.g., D13) connects to the base/gate of the transistor through a 1k-ohm to 2.2k-ohm resistor. The collector/drain connects to the positive key line of the rig, and the emitter/source connects to the rig's ground.
Then, he pressed the first memory button. : Wire a PS/2 data line and clock
Install resistors, then capacitors, then transistors, followed by headers, buttons, and finally the Arduino Nano. The nKeyer manual recommends building from the board centre outward, placing the Arduino Nano last.
Many builders prefer using pre-designed PCBs that consolidate these features: K3NG - kk9jef
A typically shows one or two keying outputs (though the code can support up to six). Each output includes a series‑base resistor and a pull‑up to +5 V on the collector side to ensure a definite high‑impedance state when the output is off. The output jack is usually a mono 3.5 mm plug that connects to the transceiver’s straight‑key input. A simple piezo buzzer or a small speaker
Arduino Nano +5V -----[10k]-----+----[Paddle Dah]---- GND | +----[Paddle Dit]----- GND
: Required for full-feature builds needing extensive memory and pins.