Add dropout tolerance (2 blocks ~40ms) to bridge brief signal gaps that
caused the state machine to chop dahs into multiple dits. Also fix scope
SNR display to use actual noise_ref instead of noise_floor.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Re-implements envelope detection on top of the rewritten Morse decoder.
Addresses PR #160 review feedback:
- Rebase: rebuilt on current upstream/main (lifecycle state machine)
- Gap thresholds: 2.0/5.0 for envelope only; goertzel keeps 2.6/6.0
- Frequency validation: max_mhz=1766 for envelope, 30 for goertzel
- Tests: EnvelopeDetector unit tests + envelope-mode decoder test
- Envelope uses direct magnitude threshold (no SNR/noise ref)
- Goertzel path completely unchanged
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The registry used plain int keys (device index), so HackRF at index 0
and RTL-SDR at index 0 would collide. Changed to composite string keys
("sdr_type:index") so each SDR type+index pair is tracked independently.
Updated all route callers, frontend device selectors, and session restore.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The previous magnitude-based threshold couldn't distinguish CW tone from
AGC-amplified inter-element silence — the Goertzel level stayed above
threshold permanently, preventing any tone OFF transitions and thus zero
character decodes.
Switch tone detection to use SNR (tone_mag / adjacent_band_noise_ref).
Both bands are equally amplified by AGC, so the ratio is gain-invariant.
Also replace the conditional noise_ref guard with unconditional blending
so the noise floor tracks actual ambient levels continuously.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The multimon-ng MORSE_CW decoder never reliably decoded characters.
Switch live decode to use the existing morse_decoder_thread() which
wraps MorseDecoder with Goertzel tone detection, adaptive thresholds,
and proper timing estimation — eliminating multimon-ng, PTY plumbing,
and the relay thread from the CW pipeline entirely.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace blocking rtl_stdout.read() with select()+os.read() so the
decoder thread emits diagnostic heartbeat scope events when rtl_fm
produces no PCM data (common in direct sampling mode). Add waiting-state
rendering in the scope canvas and hide the generic placeholder/status
bar for morse mode.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add automatic gain control (AGC) before Goertzel processing to normalize
quiet audio from direct sampling mode where the -g gain flag has no effect.
Fix broken adaptive threshold bootstrap by adding a 50-block warm-up phase
that collects magnitude statistics before seeding noise floor and signal peak.
Lower threshold ratio from 50% to 30% for better weak-CW sensitivity.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
New signal mode for decoding Morse code (CW) transmissions via SDR.
Includes route blueprint, utility decoder, frontend UI, and tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
