SDR Visual Suite

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

Features

• Live spectrum + waterfall web UI (WebSocket streaming)
• Event timeline view (time vs frequency) with detail drawer
• Event JSONL output (data/events.jsonl)
• Runtime UI controls for center frequency, span, sample rate, tuner bandwidth, FFT size, gain, AGC, DC block, IQ balance, detector threshold
• Optional GPU FFT (cuFFT) with toggle + /api/gpu
• IQ/audio recording + recordings list
• Live demod endpoint
• WFM stereo + RDS baseband
• Mock mode for testing without hardware

Quick Start (Mock)

# From repo root

go run ./cmd/sdrd --mock

Open http://localhost:8080.

SDRplay Build/Run (Real Device)

This project uses the SDRplay API via cgo (sdrplay_api.h). Ensure the SDRplay API is installed.

Windows

$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 / CUDA + SDRplay)

The only supported Windows build path in this repository is:

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

This path uses:

• nvcc + MSVC to build gpudemod_kernels.dll
• MinGW GCC/G++ for the Go/CGO application build
• runtime DLL loading for the Windows gpudemod path

Important:

• gpudemod_kernels.dll is copied next to sdrd.exe by build-sdrplay.ps1
• build-sdrplay.ps1 prepares the runtime DLL placement and PATH setup for SDRplay + CUDA DLLs
• the gpudemod DLL is built with -cudart=hybrid
• GPU validation is disabled by default for performance; enable it with SDR_GPU_VALIDATE=1 when debugging
• you can override DLL lookup with GPUMOD_DLL=C:\path\to\gpudemod_kernels.dll
• Windows builds may still show a harmless __cdecl redefined warning from CUDA headers
• older experimental Windows build scripts were removed to avoid confusion

Linux

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

Configuration

Edit config.yaml:

• bands: list of band ranges
• center_hz: center frequency
• sample_rate: sample rate
• fft_size: FFT size
• gain_db: device gain (gain reduction)
• tuner_bw_khz: tuner bandwidth (200/300/600/1536/5000/6000/7000/8000)
• use_gpu_fft: enable GPU FFT (requires CUDA + cufft build tag)
• agc: enable automatic gain control
• dc_block: enable DC blocking filter
• iq_balance: enable basic IQ imbalance correction
• detector.threshold_db: power threshold in dB (fallback if CFAR disabled)
• detector.cfar_enabled: enable OS-CFAR detection
• detector.cfar_guard_cells, detector.cfar_train_cells, detector.cfar_rank, detector.cfar_scale_db: OS-CFAR window + ordered-statistic parameters
• detector.min_duration_ms, detector.hold_ms: debounce/merge
• recorder.*: enable IQ/audio recording, preroll, output_dir, max_disk_mb
• decoder.*: external decode commands (use {iq}, {audio}, {sr} placeholders)

APIs

Config API

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

Events API

/api/events reads from the JSONL event log:

• limit (optional): max number of events (default 200, max 2000)
• since (optional): Unix milliseconds or RFC3339 timestamp

Signals API

• GET /api/signals → current live signals (latest snapshot)

Recordings API

• 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 API

• GET /api/demod?freq=...&bw=...&mode=...&sec=... → audio/wav

Decoder Tools

Put external decoder binaries/scripts under tools/ and configure decoder.* in config.yaml. See tools/README.md for examples.

Tests

go test ./...

Troubleshooting

• If you see sdrplay support not built, rebuild with -tags sdrplay.
• If the SDRplay library is not found, ensure CGO_CFLAGS and CGO_LDFLAGS point to the API headers and library.
• Use --mock to run without hardware.