- Add docs/si4684-rf-investigation-report.md: full record of the FM/DAB no-lock
investigation (crystal, front-end matching, ANTCAP sweep, continuity, leading
EP solder-defect hypothesis, PCBWay report sent) plus the separate audio
profile NVS bug found and partially fixed this session.
- Fix sigma_i2c_write() (SigmaStudioFW.c): no retry on I2C failure meant a single
transient NACK anywhere in a long safeload burst (EQ apply = ~55 sequential
transactions) aborted the whole sequence. Added a 3-attempt retry.
- Add granular failure logging (AudioService::applyProfileToDsp/persistProfile,
Adau1701Driver::applyMixer/applyEq, NvsAudioProfileStore::saveProfile error
codes) to isolate the remaining NVS-side audio profile save failure.
- Si4684Driver::tuneFm gains an optional ANTCAP argument (default 0 = unchanged
auto-tune behavior) used during this session's front-end matching sweep.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Safeload mixer/EQ/master on the ADAU1701, persist AudioProfile in NVS,
expose /api/audio routes and web UI controls, with host tests and manual sync.
Co-authored-by: Cursor <cursoragent@cursor.com>