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N0JCG-SCANNER v1.0.0

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@bakstaaj bakstaaj released this 26 Jul 04:57
· 170 commits to main since this release
v1.0.0
8f1ec0a

PI-P25-SCANNER v1.0.0

PI-P25-SCANNER v1.0.0 is the first major stable release of the dedicated
Raspberry Pi P25 trunked-radio scanner. It establishes a validated
multi-receiver OP25 architecture with independent control and voice
demodulation, reliable browser audio, receiver-role protection, and truthful
runtime status.

Validated production architecture

  • Raspberry Pi 5 running the P25 scanner backend and web interface.
  • Dedicated control receiver:
    • RTL serial 00000251
    • CQPSK demodulation
    • LNA:40
  • Dedicated voice receiver:
    • RTL serial 00000252
    • FSK4 demodulation
    • LNA:49
  • OP25 multi_rx.py runtime with one protected control receiver and scalable
    dedicated voice receivers.
  • Backend and web interface on TCP port 8070.
  • Raw browser-audio endpoint on TCP port 8072.
  • OP25 per-receiver UDP audio pool on ports 23500 through 23509.
  • Selected audio forwarded to the existing browser bridge on UDP port 23456.

P25 control-channel behavior

  • Sticky control-channel operation tolerates consecutive framing timeouts before
    hunting fallback channels.
  • Tenderfoot II effective control-channel list:
    • 853.300000 MHz
    • 853.537500 MHz
    • 853.750000 MHz
  • 852.225000 MHz is excluded from control-channel scanning but remains
    available for dynamically assigned voice traffic.
  • The dedicated control receiver uses an impossible TGID whitelist entry so it
    cannot be consumed by a voice grant.

Voice and browser-audio behavior

  • Independent control and voice demodulator settings.
  • FSK4 voice decoding produces active, intelligible Phase I PCM where CQPSK
    voice produced effectively silent PCM.
  • Audio-pool minimum RMS threshold: 25.
  • Per-burst acquisition warm-up: eight 20 ms frames, approximately 160 ms.
  • OP25 DRAIN and DROP UDP flags are decoded as explicit audio-burst
    boundaries.
  • The selected voice source remains held through quiet speech while PCM packets
    continue arriving.
  • Lost-packet safety release occurs after 2.5 seconds without PCM.
  • Audio sources are selected without mixing.

Runtime and UI improvements

  • Receiver inventory and persistent receiver-role registry.
  • Scalable multi-receiver state and configuration telemetry.
  • Truthful control and voice frequency reporting.
  • Voice-assignment and audio-pool activity counters.
  • Balanced UI polling to avoid excessive backend load.
  • Rotating OP25 runtime log:
    • 8 MiB active log
    • five retained backups
  • Control-frequency parsing no longer misclassifies unqualified voice tuning
    messages as control-channel changes.

Hardware role registry

The validated seven-receiver inventory preserves these assignments:

Role RTL serial
P25 control 00000251
P25 voice 00000252
NOAA / airband 00000162
ADS-B 1090 00001090
UAT 978 00000978
Analog 2 m 00000440
Analog 70 cm 00000144

Only the P25 services are part of this release runtime. Other assigned receivers
remain reserved for their associated applications or later phases.

Final hardware validation

The v1.0.0 release state was validated on July 23, 2026 against Colorado DTRS
Tenderfoot II, RFSS 6, Site 017.

Final flag-aware audio validation observed:

  • three actual decoded audio bursts;
  • 216 PCM frames;
  • 64 active PCM frames;
  • 24 acquisition frames suppressed, exactly eight per audio burst;
  • 122 stabilized PCM frames forwarded;
  • 15 OP25 DRAIN flags;
  • three selected-stream boundary events;
  • zero timeout-driven source releases;
  • zero audio output errors.

The user confirmed that audio quality and continuity were substantially improved
after the flag-aware call-boundary and source-hold changes.

Important limitations

  • Encrypted P25 traffic cannot be decoded.
  • The first approximately 160 ms of each selected voice burst is intentionally
    suppressed to remove unstable acquisition audio.
  • v1.0.0 was hardware-validated with one dedicated voice receiver. The
    architecture supports adding more matching P25 voice receivers.
  • This source release does not contain site credentials, RadioReference
    credentials, runtime logs, generated local settings, or other device-specific
    secrets.

Release lineage

  • Recovery/main checkpoint:
    a83da5307636ebf32deece49b2ad9a2639837c44
  • Validated Phase 32 audio-boundary commit:
    1de841591071fb693f20aa40929cd707cb6d0d07
  • Release branch:
    feature/scalable-p25-multi-rx-v2
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