NeoLDG

NeoLDG is a fresh Qt 6 desktop controller for LDG autotuners that expose the meter/control protocol over a TTL serial connection.

Current model presets:

• LDG-1000ProII
• LDG-600ProII

This project intentionally focuses on the tuner itself:

• serial connection over a USB-to-TTL adapter
• selectable tuner model with model-specific watt calibration
• live forward/reflected power telemetry
• SWR and band display
• memory tune, full tune, bypass, antenna toggle, and auto/manual mode controls
• modern desktop UI with persisted settings

Why a fresh implementation?

The original LDGControl project is a useful reference for command behavior and workflow, but NeoLDG is implemented from scratch with a new UI and a separate Qt-based architecture so it can be maintained and published cleanly.

Build

Requirements:

• CMake 3.21+
• C++20 compiler
• Qt 6 with Core, Widgets, and SerialPort

Build commands:

cmake -S . -B build
cmake --build build -j
./build/NeoLDG

Releases

GitHub Releases are built automatically from version tags.

• Windows releases are published as a portable .zip bundle with the required Qt runtime files.
• Linux releases are published as an AppImage.

Diagnostics

NeoLDG creates a diagnostic log file on each launch and keeps the most recent logs in the app data folder. The Diagnostics panel shows the current log path, opens the log folder, and can enable verbose logging for serial byte stream and meter parser recovery details.

Verbose logs are especially useful when debugging stream alignment loss, USB serial dropouts, or suspected RFI-related serial corruption.

Hardware Notes

• Use a TTL-level serial adapter, not a full RS-232 port.
• The tuner side expects the LDG mini-DIN wiring used by the original control cable.
• Before you use an S-Video Cable, please be sure the two "ground" pins are not tied together, some cheaper cables do this, this will kill your tuner.

Protocol Summary

NeoLDG follows the observed LDG control flow used by the original utility:

• send a wake byte (0x20, space) before each command
• wait about 1 ms before sending the actual command byte
• use X to enter control mode before command/response interactions
• use S to resume streaming meter telemetry
• parse meter frames as 6 bytes of payload followed by ;;

The LDG-600ProII preset uses the same control protocol with a reduced power calibration for watt display.