Confirmed live tonight that the Si4684's automatic front-end tuning
(FE_VARM/VARB properties) is measurably suboptimal on this board: a
129-value ANTCAP sweep (0-128, AN851 Appendix A) at four different FM
frequencies found antcap=102 beats auto-tune by +6 to +11 dB RSSI and
+3 to +11 dB SNR everywhere tested, consistent with the front-end
network component mismatch already logged in
docs/si4684-rf-investigation-report.md — the board's actual matching
network differs from the AN851 reference network those auto-tune
constants were derived from, so a fixed empirical override
compensates for a gap the chip's own algorithm can't see.
Wiring, bottom to top:
- Si4684Driver::tuneFm() already took an antCap byte; threaded it
through core::ITuner::tuneFm() and si4684::Si4684Tuner::tuneFm() as
a new parameter (default 0 = auto, unchanged behaviour for every
existing caller).
- TunerService::tuneFm() takes an optional override instead: omitted,
it falls back to a new defaultFmAntCap_ member so every ordinary FM
tune (seek, scan, station recall, live UI) benefits automatically
once calibrated, not just calls that pass antcap explicitly.
- POST /api/tuner/tune gained an optional "antcap" field for sweeping
live without touching the saved calibration.
- POST /api/tuner/calibrate-antenna commits a sweep result: writes it
to the 24AA025E48 EEPROM's user-writable region (word address 0x00,
separate from the factory-locked EUI-48 at 0xFA-0xFF) via a new
Eeprom24aa::writeFmAntCap()/readFmAntCap() pair, and immediately
updates the live TunerService default — no reboot needed to take
effect, though HardwareBootstrap::boot() also loads it at every
boot so it survives power cycles. Same net::AntennaCalibration
function-pointer bridge pattern as PhoneStreamSink/BleProvisioning,
so components/net stays free of eeprom24aa headers.
Verified end to end on hardware: swept and found 102, saved it via
the new endpoint, confirmed the live default changed immediately,
then power-cycled and confirmed the boot log reports "FM ANTCAP
calibration loaded: 102" and a subsequent default tune reflects it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
Read the factory 24AA025E48 serial after ADAU I2C boot, derive SoftAP SSID, BT name, STA hostname, and expose serialNumber on GET /api/health with graceful fallbacks.
Co-authored-by: Cursor <cursoragent@cursor.com>
Expose discoverable mode and A2DP control over REST, add persisted
DAB/FM preset list with web UI, and document gaps in docs/TODO.md.
Co-authored-by: Cursor <cursoragent@cursor.com>
Expose Si4684, ADAU1701, and BT1035 boot flags via CompanionChipStatus after
HardwareBootstrap; update API manual schema for Slice 8.
Co-authored-by: Cursor <cursoragent@cursor.com>
Implement Bt1035Driver AT init (AT+AUXCFG=1), core AT parser with host tests,
wire boot into HardwareBootstrap, and document DAB/FM tuning workflows in ch-si4684.
Co-authored-by: Cursor <cursoragent@cursor.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>