micheleandClaude Sonnet 5
fae2305164
Root cause of FM/DAB "stonata" audio: xtalCtun=31/nominal XTAL_FREQ defaults were never measured against this board's actual crystal (Abracon ABM8-19.200MHZ-10-1-U-T, CL=10pF, two external 15pF load caps). Fixed via CTUN trim by ear (31->0) plus a new live calibration loop that reads the Si4684's own FM_RSQ FREQOFF field (broadcast carriers are GPS-locked, so it's a free precision frequency reference) to trim XTAL_FREQ with no lab equipment. Converged to CTUN=0, XTAL_FREQ=19199750 Hz, residual -3/-4 ppm cross-checked on two stations. New tools/infrastructure (kept, not one-off): - Si4684Driver::recalibrateXtal() + POST /api/tuner/xtal-calibrate: live crystal re-trim without an ESP32 reflash. - FM_RSQ FREQOFF exposed as "freqoff_ppm" in GET /api/tuner/status. - tools/si4684_xtal_calibration.py: automates the trim loop. - tools/si4684_antenna_calibration.py: AN851 Appendix A ANTCAP/VARM/VARB sweep tool (same session, separate calibration). - CONFIG_ESP32_I2S_TEST_TONE (off by default): isolates Si4684-specific audio issues from shared-downstream ones by writing a tone directly over the I2S bus the Si4684 also uses. - SIGMA_WRITE_REGISTER_BLOCK/sigma_safeload_block now retry on NACK and verify via read-back instead of firing I2C writes blind. - FM de-emphasis set to European 50us (was left at the US 75us default). - DAB_ACF_ENABLE restored to its previous 0x0000 with a citation explaining why (tested the datasheet default of 0x0003, made things audibly worse). See docs/si4684-rf-investigation-report.md's 2026-08-23 entry for the full elimination chain and docs/TODO.md for follow-up work (persisting calibration results to EEPROM instead of requiring a firmware edit). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
ADAU1701 SigmaStudio export
SigmaStudio project DigiRadio, IC1 = ADAU1701. Shipped with DigiRadio firmware 0.8.3.
Key files
| File | Role |
|---|---|
DigiRadio_IC_1.h |
Program/param RAM data + default_download_IC_1() |
DigiRadio_IC_1_REG.h |
Control register map (safeload trigger) |
DigiRadio_IC_1_PARAM.h |
Parameter cell indices (ADDR_*) |
DigiRadio_NetList.xml |
Schematic netlist (reference) |
SigmaStudioFW.h |
Safeload / I2C glue API |
Runtime (fw 0.8.3)
- Boot: ESP32 replays the active
DspProgramover I2C viaadau1701::Adau1701Driveron every power-up. Source order: valid blob in thedspflash partition, else the embedded export from this folder (EmbeddedDspProgramSource). - Program update:
POST /api/dsp/programwith aDRADv1 blob (seeSoftware/tools/pack_dsp_program.py). Device reboots and loads the new script on next boot. - Live control: six-band PEQ, input mixer, master volume, stereo/bass
enhancement overlays — safeload via
audio::AudioServiceand REST/api/audio/*; profile persisted in encrypted NVS. - Web UI: Audio tab — 6 EQ sliders + mixer/enhance controls.
I2C address: 7-bit 0x34 (ADDR0=ADDR1=GND). Sample rate: 48 kHz.
Safeload implementation: components/drivers/adau1701/src/SigmaStudioFW.c.
Parameter map: components/drivers/adau1701/include/adau1701/Adau1701ParamMap.hpp.
After re-exporting from SigmaStudio
- Action → Export System Files into this folder (overwrite headers).
- Reconcile new
ADDR_*symbols inAdau1701ParamMap.hppif block names moved. - Rebuild and flash firmware (
idf.py build). - Update manual:
docs/manual/ch-sigmastudio.tex,docs/manual/ch-adau1701.tex.
Do not use SigmaStudio Link Compile Download on DigiRadio — export only; the ESP32 programs the DSP at every power-up.
DRAD v1 blob (flash / HTTP upload)
Layout: magic DRAD, version u16 (=1), write count u16, CRC32 (IEEE over
writes section), then for each write: address u16, length u16, data bytes.
Pack from JSON with Software/tools/pack_dsp_program.py or use
core::serializeDspProgramBlob() in host tests.
Documentation
- Design:
docs/manual/ch-sigmastudio.tex - Driver & API:
docs/manual/ch-adau1701.tex - HTTP:
docs/manual/ch-api.tex(/api/audio/*)