SDR Visual Suite

Go-based SDRplay RSP1b live spectrum + waterfall visualizer with event tracking, classifier, and demod/recording pipeline.

Features

• Live spectrum + waterfall web UI (WebSocket streaming)
• Event timeline view (time vs frequency) + detail drawer
• Live signal list + classifier insights
• Runtime UI controls: center, span, sample rate, tuner bandwidth, FFT size, gain, AGC, DC block, IQ balance, detector settings
• Optional GPU FFT (cuFFT) + /api/gpu
• IQ/audio recording + recordings list
• Live demod endpoint + WebSocket live-listen audio
• WFM stereo + RDS baseband
• Mock mode for testing without hardware

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Requirements

Core

• Go 1.22 (see go.mod)

Optional (real device)

• SDRplay API (sdrplay_api.h + library)

Optional (GPU)

• CUDA toolkit (cuFFT)
• nvcc for kernel build (Linux) or build-gpudemod-dll.ps1 (Windows)

Windows build prerequisites (real device + GPU)

• MSYS2 MinGW64 (C:\msys64\mingw64\bin\gcc.exe / g++.exe) for CGO
• SDRplay API installed (default path in scripts)
• CUDA toolkit (default paths in scripts)

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Quick Start (Mock Mode)

# From repo root

go run ./cmd/sdrd --mock

Open http://localhost:8080.

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Configuration

Edit config.yaml (autosave goes to config.autosave.yaml).

Common fields:

• center_hz, sample_rate, fft_size, gain_db, tuner_bw_khz
• use_gpu_fft, agc, dc_block, iq_balance
• detector.* (e.g. threshold_db, cfar_mode, cfar_guard_hz, cfar_train_hz, min_duration_ms, hold_ms, ...)
• recorder.* (enable IQ/audio recording, output path, ring buffer, etc.)
• decoder.* (external decoder commands)

CFAR modes: OFF, CA, OS, GOSCA, CASO

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Build & Run (Windows)

Mock / No SDRplay

go build ./cmd/sdrd
.\sdrd.exe --mock

SDRplay (Real Device)

$env:CGO_CFLAGS='-IC:\Program Files\SDRplay\API\inc'
$env:CGO_LDFLAGS='-LC:\Program Files\SDRplay\API\x64 -lsdrplay_api'

go build -tags sdrplay ./cmd/sdrd
.\sdrd.exe -config config.yaml

Windows (GPU + SDRplay) — recommended path

powershell -ExecutionPolicy Bypass -File .\build-cuda-windows.ps1
powershell -ExecutionPolicy Bypass -File .\build-sdrplay.ps1

This path:

• Builds gpudemod_kernels.dll (MSVC/nvcc)
• Builds Go app with MinGW64 CGO + tags sdrplay,cufft
• Copies CUDA runtime DLLs next to sdrd.exe

Notes:

• build-sdrplay.ps1 expects MinGW at C:\msys64\mingw64\bin
• CUDA DLLs are copied if found (see script for exact paths)
• Override the GPU DLL path with GPUMOD_DLL=C:\path\to\gpudemod_kernels.dll

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Build & Run (Linux)

SDRplay (Real Device)

export CGO_CFLAGS='-I/opt/sdrplay_api/include'
export CGO_LDFLAGS='-L/opt/sdrplay_api/lib -lsdrplay_api'

go build -tags sdrplay ./cmd/sdrd
./cmd/sdrd/sdrd -config config.yaml

CUDA kernel build (GPU demod)

./build-cuda-linux.sh

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APIs

Config

• GET /api/config
• POST /api/config
• POST /api/sdr/settings
• GET /api/gpu

Signals / Events

• GET /api/signals → current live signals
• GET /api/events?limit=&since= → recent events

Recordings

• GET /api/recordings
• GET /api/recordings/:id (meta.json)
• GET /api/recordings/:id/iq
• GET /api/recordings/:id/audio
• GET /api/recordings/:id/decode?mode=FT8|WSPR|DMR|D-STAR|FSK|PSK

Live Demod / Listen

• GET /api/demod?freq=...&bw=...&mode=...&sec=... → audio/wav
• WS /ws/audio?freq=...&bw=...&mode=... → live PCM audio stream

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Decoder Tools

Put external decoder binaries/scripts under tools/ and configure decoder.* in config.yaml. Placeholders: {iq}, {audio}, {sr}. See tools/README.md for examples.

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Tests

go test ./...

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Troubleshooting

• sdrplay support not built → rebuild with -tags sdrplay.
• SDRplay library not found → check CGO_CFLAGS / CGO_LDFLAGS.
• GPU demod not loading → verify gpudemod_kernels.dll / cudart64_13.dll next to sdrd.exe (Windows).
• Use --mock to run without hardware.