fm-rds-tx/RELEASE.md

Release Notes — v0.6.0-pre

Hardware-ready milestone

The system is now ready for first real hardware TX tests with ADALM-Pluto (PlutoSDR).

Build for PlutoSDR

go build -tags soapy ./cmd/fmrtx
.\fmrtx.exe --list-devices
.\fmrtx.exe --tx --config docs/config.plutosdr.json

What's proven

• 82 tests pass (DSP, spectral, operator truth, engine)
• FM IQ magnitude verified: all samples |I²+Q²| = 1.000000
• Spectral verification: 19 kHz pilot, 38 kHz stereo, 57 kHz RDS confirmed
• Continuous TX engine runs stable for >60s in tests
• IQ resampling 228k→528k preserves signal magnitude

First smoke test procedure

1. Connect PlutoSDR via USB
2. .\fmrtx.exe --list-devices — verify device shows up
3. .\fmrtx.exe --tx --config docs/config.plutosdr.json — start in idle mode
4. curl -X POST http://localhost:8088/tx/start — begin transmitting
5. Tune FM receiver to 100.0 MHz — should hear 1kHz/1.6kHz test tones
6. curl http://localhost:8088/runtime — check telemetry
7. curl -X POST http://localhost:8088/tx/stop — stop
8. Ctrl+C to exit

Safety defaults

• TX is OFF by default — requires explicit start
• outputDrive 0.3 in PlutoSDR config (conservative)
• Limiter enabled with ceiling 1.0
• Pre-emphasis 50µs (European standard)