okSDR - for Xiegu G90

A high-performance Software Defined Radio (SDR) receiver, panadapter, and transceiver companion built in Rust for the Xiegu G90 HF transceiver (Firmware 1.81).

okSDR provides real-time dual waterfalls (RF spectrum and demodulated AF audio), smooth 60 FPS GPU-accelerated rendering, an integrated CW decoder, an audio recording & playback deck, one-click SSB calling frequency band switching, and configurable I/Q audio input and CAT control.

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Features

Dual Waterfall & Spectrum (HDSDR Style)

• RF Panadapter & Waterfall (±48 kHz / 96 kHz Span):
  • Centered on the Xiegu G90 VFO frequency in real-time.
  • GPU-accelerated waterfall with selectable color palettes (Viridis, Inferno, Turbo, Classic SDR, High Contrast).
  • Spectrum floor, dynamic range, and ratio adjustments with peak-hold line.
  • Click anywhere in the passband to tune, Shift-click to retune the radio VFO, or use the mouse wheel to tune in 1 kHz steps.
• AF Audio Spectrum & Waterfall (0 to 4 kHz):
  • Zoomed view of demodulated audio showing carrier, voice formants, CW sidetone, and filter skirts.
  • Resizable splitter panel with persistent height adjustment.

Xiegu G90 Rig Control (CAT)

• Bi-Directional Frequency & Mode Sync: Spinning the physical dial on the G90 instantly updates okSDR, and clicking frequencies or modes in okSDR commands the G90 via Hamlib rigctld.
• Live Connection Status: Real-time CAT status indicator with an automatic reconnection watchdog.
• Calibrated S-Meter: Digital bar meter showing accurate signal strength from S1 to S9, +10 to +80 dB over S9, and numeric dBFS readouts.

Quick SSB Band Switcher & Calling Frequencies

• 9 Dedicated SSB Band Buttons: Quick-switch between the 9 HF bands authorized for SSB voice: 160m, 80m, 60m, 40m, 20m, 17m, 15m, 12m, and 10m (excludes 30m where voice is prohibited).
• Direct Calling Frequency Tuning: Pressing any band button automatically commands the G90 and VFO to the widely recognized national/international SSB calling frequency, selects the correct sideband (LSB on 160m/80m/40m, USB on 60m–10m), and sets appropriate filter bandwidth:
  • 160m: 1.9100 MHz LSB
  • 80m: 3.9850 MHz LSB
  • 60m: 5.3305 MHz USB (Channel 1)
  • 40m: 7.1850 MHz LSB
  • 20m: 14.2850 MHz USB
  • 17m: 18.1500 MHz USB
  • 15m: 21.3850 MHz USB
  • 12m: 24.9500 MHz USB
  • 10m: 28.4000 MHz USB
• Activity Presets Dropdown: Instant shortcuts to CW calling frequencies, FT8 digital spots, and voice nets.
• Per-Band Memory: Automatically remembers the last tuned frequency across all bands.

CW Mode & Integrated Morse Decoder

• Real-Time Morse Decoder:
  • Auto-scrolling decoded text ticker embedded in the AF waterfall bar, active when operating in CW mode.
  • Automatic WPM speed detection.
  • Real-time ● TONE detection indicator dot.
  • Pause, resume, and clear controls.
• Selectable CW Pitch: Dedicated pitch buttons (600 Hz, 700 Hz, 800 Hz) that center the filter passband.
• Waterfall Alignment Offset: Aligns waterfall carrier clicks directly with the CW sidetone so clicking a signal on the waterfall tunes the radio to the exact matching pitch.

RX Audio Recording Deck

• Live Waveform Display: Visualizes received audio in real-time as it is recorded.
• Deck Controls: Record, Play, Pause, Stop, and clear recordings.
• Interactive Scrubbing: Scrub cursor with mouse wheel scrubbing to review received signals.
• Automatic WAV Export: Saves standard 48 kHz uncompressed WAV files into ~/okSDR_Recordings/ with metadata-rich filenames including start timestamp, band, mode, and frequency.
• Recent Recordings Menu: Quick recall of recent audio takes for instant playback.

Hardware Configuration (⚙ CONFIG)

• I/Q Audio Input Selection: Choose your sound card or stereo Line-In interface from a dropdown list with a refresh button.
• CAT Serial Port Selection: Select your G90 serial port (/dev/serial/by-id/*, /dev/ttyUSB*, /dev/ttyACM*, or custom entry) with a Test CAT button for immediate verification.
• I/Q Balance & Squelch (SQL) Calibration:
  • DC offset notch removal filter.
  • I/Q channel swap (sideband inversion).
  • Amplitude gain balance and phase balance sliders.
  • Squelch threshold (SQL) slider (-130 to 0 dBFS).

Demodulators & Audio DSP

• Modes: USB, LSB, CW, AM, FM.
• Filter Passband: Independent Left and Right filter edge adjustment (50 Hz steps), or quick presets: 2.4k, 1.8k, 500Hz, Wide.
• AGC & Gain: Multi-speed AGC (Off, Slow, Med, Fast) with hang time, plus manual gain adjustment when AGC is off.
• RF Preamp Gain: Digital RF preamp slider boosting incoming Line-In audio by 0 to +36 dB.
• Auto-Save: User settings, volume, filter edges, and band memories persist across app restarts.

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Hardware Connections

1. Audio I/Q Cable:
   • Connect a 3.5mm stereo cable from the Xiegu G90 rear I/Q jack to your sound card's stereo Line-In.
2. CAT Serial Cable:
   • Connect the Xiegu G90 CAT cable to a USB port on your PC (detected as /dev/ttyUSB* or /dev/serial/by-id/*).

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Installation & Setup

Dependencies

Install the required system packages:

# Debian / Ubuntu / Linux Mint
sudo apt update
sudo apt install -y build-essential libasound2-dev libudev-dev libhamlib-utils git

Ensure your user account has access to serial ports:

sudo usermod -aG dialout $USER
# Log out and back in for permissions to take effect

Building from Source

1. Install Rust via rustup:

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   source "$HOME/.cargo/env"

2. Clone this repository:

   git clone https://github.com/Ch33s3man/okSDR.git
   cd okSDR

3. Build the release binary:

   cargo build --release

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Launching

Launcher Script (Recommended)

Use the included run.sh script to launch okSDR:

./run.sh

On startup, okSDR presents a Radio Connection screen where you can:

• Review or choose your serial port (/dev/ttyUSB*, /dev/serial/by-id/*, etc.)
• Select the G90 baud rate (19200 default) and CI-V address (0x70)
• Click Test CAT to safely query the G90's frequency and mode (with DTR/RTS held strictly LOW so the transmitter is never keyed)
• Click Connect to initialize Hamlib rigctld (Model 3088) with full PTT protection (dtr_state=OFF,rts_state=OFF,ptt_type=None)
• Or click Continue without CAT to run the SDR in audio/visual mode without rig sync.

Desktop Shortcut

To create a desktop shortcut:

cp okSDR.desktop ~/Desktop/
chmod +x ~/Desktop/okSDR.desktop

Then double-click the okSDR icon on your Desktop.

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Operating Shortcuts

Action	Control / Shortcut
Tune Frequency (VFO)	Left-click anywhere on the RF spectrum / waterfall
Retune Radio LO / Center	Shift + Left-click on the RF spectrum
Fine Frequency Tuning	Mouse wheel scroll over RF spectrum / waterfall (snaps to 1 kHz)
Adjust Filter Bandwidth	Drag Left / Right edge sliders or mouse-wheel scroll on slider
Quick Filter Presets	Click 2.4k, 1.8k, 500Hz, or Wide
CW Pitch Adjustment	Click 600Hz, 700Hz, or 800Hz (CW mode only)
SSB Calling Frequencies	Click any band button (160m through 10m)
Audio Recording Deck	Click [● REC DECK] to toggle waveform drawer
Scrub Audio Recording	Drag scrub bar or scroll mouse wheel over recorded waveform
Hardware Configuration	Click [⚙ CONFIG] to select audio input, serial port, or test CAT

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License

okSDR is open-source software licensed under the GNU General Public License v3.0 (GPL-3.0-or-later). See the LICENSE file for details.

Developed by KE2JBD and Antigravity. Contributions and pull requests from the amateur radio community are welcome!