K3ng Keyer Schematic !free! -

Most standard K3NG keyer schematics revolve around a 5V Arduino-compatible microcontroller (typically an , Uno , or Mega 2560 ). However, the K3NG firmware also supports STM32 and Teensy boards. Let’s examine the fundamental blocks.

If you experience hum or noise when connecting the keyer to a computer and a radio simultaneously, ensure your optocoupler circuit is wired correctly to isolate the grounds.

Internal pull-up resistors are enabled via software, but standard schematics include a 0.01µF to 0.1µF capacitor from each line (Dit and Dash) to ground to filter out RF interference (RFI) straying from your transmitter. 2. Transmitter Keying Output Circuit

Configure the keyer_pin_settings.h file to match your schematic. Upload the code to the Arduino. Advanced Options in the Schematic k3ng keyer schematic

If any function does not work, re‑check the schematic connections and the pin assignments in the header files. Most build issues are due to a mismatched pin definition or a cold solder joint.

Safely interface Arduino’s 5V logic to the transceiver’s key input (which may be 0–12V, high impedance, or require current sinking).

The paddle circuit connects your iambic paddle to the Arduino. Most standard K3NG keyer schematics revolve around a

A complete K3NG keyer schematic is modular. You can add or remove sections depending on the features you want to build. 1. The Paddle Input Circuit

A piezo buzzer or speaker for sidetone, connected via a resistor or capacitor.

Connected between an Arduino output pin (e.g., D13) and Ground. A small capacitor (e.g., If you experience hum or noise when connecting

Up to 12 memory buttons can be added, typically using a resistor ladder on a single analog pin to save space. Input Devices: Interfaces for PS/2 keyboards or USB host shields for computer-less keyboard operation.

Paddle inputs