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K3ng Keyer Schematic ~repack~ Today

The K3NG Keyer is a highly versatile, open-source Morse code keyer based on the Arduino platform, developed by Anthony Good (K3NG). Because it is designed to be modular and feature-rich, the "schematic" can range from a simple breadboard setup to complex PCB designs incorporating LCDs, rotary encoders, and multi-rig switching. Core Schematic Components

The foundation of most K3NG builds includes these primary circuit blocks: HL2 and OpenCWKeyer K3NG Winkeyer - Google Groups k3ng keyer schematic

31 Jul 2023 β€” For this example this is pin 12. - for the schematic provided as an example : # define tx_key_line_1 12 // (high = key down/tx on) Google Groups CW Keyer - kk9jef The K3NG Keyer is a highly versatile, open-source

A "Real-Time Visual Morse Decoder with Input Validation & Sidetone Feedback" would be a highly useful feature to add to the k3ng keyer schematic (especially for Arduino-based builds). A Brief History: Why the K3NG Keyer Exists

A Brief History: Why the K3NG Keyer Exists

Before diving into the schematic, it is vital to understand the why. Traditional keyers (like the Bencher BY-1 or commercial Logikey) are locked into firmware. What you buy is what you get. K3NG wanted a keyer that could handle:

  • Iambic A/B modes
  • Ultimatic mode
  • Squeeze keying
  • Keyboard memory (sending pre-set messages)
  • PS2 keyboard input
  • Serial (RS-232) control
  • Rotary encoder tuning
  • LCD displays (16x2 or 20x4)
  • Beacon mode
  • Pin diode FSK for RTTY

Because the code runs on an Arduino, the schematic is simply the wiring map to unlock these features. You can build a minimal keyer with three wires, or a deluxe command station with 40 components. The schematic scales with you.

2.11 Activity/TX LEDs

  • Simple LED + 220Ξ© resistor to GND from Arduino pin.

Common Wiring Notes

  • Configure pins in K3NG's config.h to match your wiring.
  • Use INPUT_PULLUP in firmware if wiring switches to ground.
  • Keep keying wires short and twisted to reduce RF pickup; add ferrite beads if needed.
  • If your transceiver expects a closure to ground for keying, transistor/optocoupler must provide that closure.
  • For FSK keying (AFC/FSK shift), check radio’s required voltage levels and whether it needs open-collector vs. grounded closure.

Feature Overview

  • What it does: Monitors the key/paddle inputs, decodes Morse code in real time, displays characters on an LCD/OLED, and alerts the user if a timing or electrical issue is detected (e.g., stuck key, incorrect wiring, or malformed code).
  • Why it’s useful: Helps beginners verify wiring, diagnose keying issues, and learn Morse without a separate decoder.

2.4 Sidetone & Speaker

  • Arduino pin (PWM capable) β†’ Low-pass filter (RC, e.g., 1kΞ© + 0.1Β΅F) β†’ Audio amplifier (e.g., LM386) or passive piezo.
  • On some simplified schematics: just a piezo buzzer with series resistor (100Ω–470Ξ©).

2.1 Microcontroller (Arduino)

  • Typical: Arduino Nano (ATmega328P) or Mega 2560.
  • Pins used (example for Nano):
    • D3 – Paddle dot (dit)
    • D4 – Paddle dash (dah)
    • D5 – Speed pot (analog)
    • D6 – Straight key input
    • D7 – PTT output
    • D8 – Keyer output (to radio)
    • D9 – Sidetone output (PWM)
    • D10 – Activity LED
    • D11 – TX LED
    • D12 – Rotary encoder A
    • D13 – Rotary encoder B
    • A4/A5 – I2C LCD

2.5 Speed Potentiometer

  • 10kΞ© linear pot between +5V and GND, wiper to analog input (e.g., A0).
  • Firmware reads ADC and maps to 5–50 WPM.