The Feasycom BT1035 programming user guide's own pin table (§2.2, pin
34 SYS_CTRL) reads "Delay 100ms, pull high" -- the previous reset
sequence here asserted SYS_CTRL high at the very same instant as
RESET, with zero lead-in delay, racing the module's own documented
power-on requirement (the datasheet's §4.7 separately confirms
SYS_CTRL must be asserted >20ms before internal regulators even start
powering up). Rewrote resetAndInitOnce() to hold both pins low for a
100ms lead-in matching the guide exactly, then bring SYS_CTRL high,
then an extra 50ms settle margin before releasing RESET into a module
that's had a chance to actually power up first.
This is verified correct against the manufacturer's own documented
timing and is worth keeping regardless of its effect on any one
symptom, but it does NOT fully explain this project's intermittent
BT1035 boot failures ("no spontaneous UART bytes after hardware
reset"): a deep investigation session confirmed the same failure
still occurs, at the same rate, across genuine physical power cycles
(not just soft resets) with this fix applied, extended UART listen
windows (tested up to 10s vs the normal 3.5s), and independently
schematic-verified-correct GPIO pin assignments, UART TX/RX wiring,
AT command bytes, and shared 3.3V regulator sizing. Unlike the
Si4684 ARG1-offset bug earlier this session -- which failed 100% of
the time, deterministically, from a real code defect -- this failure
is non-deterministic across identical power-on sequences with
identical code, which does not match a firmware logic-bug signature.
Root cause remains open; see docs/si4684-rf-investigation-report.md.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
DigiRadio Firmware
Open-source Hi-Fi DAB+/FM receiver firmware for the ESP32-S3.
Status: fw 0.8.5 on main — BT1035 I2S slave boot init, dual OTA + DSP blob updates, EEPROM identity,
NVS + flash encryption (development mode), tabbed Web UI with System uploads,
15 host tests, 4 CI jobs. Agent tasks T1–T12 complete; device HIL pending
first PCB.
| Area | Shipped in 0.8.5 |
|---|---|
| Boot | Si4684 HOST_LOAD, ADAU1701 RAM program, BT1035 I2S slave init (AUXCFG=3, I2SCFG=67) |
| Tuner | FM/DAB tune, seek up/down, RSQ, RDS, DAB services + DLS |
| Audio | 6-band EQ, mixer, stereo/bass enhance, NVS profile |
| Updates | ESP32 dual-OTA, ADAU1701 dsp partition blob replay |
| Identity | 24AA025E48 EUI-48 → serial, SoftAP/BT name suffix |
| Presets | CRUD, reorder, integrated recall + last-preset at boot |
| Network | SoftAP/STA, tabbed gzipped SPA, typed JSON REST API |
| Security | initEncryptedStorage() — see docs/security-flash-nvs.md |
| Quality | Doxygen, manual sync, Si4684 blob policy check |
Architecture: functional core (components/core, host-tested, no ESP-IDF) +
imperative shell (drivers, services, net, secure_store). Rules:
AGENTS.md · backlog: docs/TODO.md
Prerequisites
Si4684 blobs (proprietary, local only — not in git):
python3 tools/fetch_si4684_firmware.py --dab-only
python3 tools/fetch_si4684_firmware.py --si46xx-dir /path/to/si46xx_firmware
python3 tools/check_si4684_blobs.py
See Firmware/Si4684-Firmware/README.md.
ESP-IDF v5.5.x, target esp32s3.
Quick start
Open this directory (Software/) as the Cursor project so AGENTS.md and
.cursor/rules/ load automatically.
idf.py set-target esp32s3
idf.py build
idf.py erase-flash flash # once when first enabling encryption (0.8.3+)
idf.py -p <port> monitor
Production flash-encryption release mode: overlay sdkconfig.defaults.production
(see security doc — irreversible on chip).
Host tests
Pure core, no hardware (needs C++23 compiler on macOS — Homebrew llvm or GCC 14):
cmake -S components/core/test -B build-host \
-DCMAKE_CXX_COMPILER="$(brew --prefix llvm)/bin/clang++"
cmake --build build-host
ctest --test-dir build-host --output-on-failure
Quality gates (CI on every push to main)
Run from Software/:
doxygen Doxyfile
python3 tools/check-manual-sync.py
python3 tools/check_si4684_blobs.py
tools/gzip-www.sh # after editing components/net/www/index.html
CI jobs: host-tests, doxygen, manual-sync, si4684-blobs
(.github/workflows/ci.yml).
Web UI
Gzipped single-page app at / — tabs: Now (RDS/DLS), Radio, Presets,
Audio (6-band EQ), BT, Wi‑Fi, System (firmware OTA + DSP upload).
Header shows EEPROM serial from /api/health. Source:
components/net/www/index.html · regenerate embed:
tools/gzip-www.sh.
HTTP API (fw 0.8.5)
| Method | Path | Purpose |
|---|---|---|
| GET | /api/health |
Status, firmware version, serial, companion-chip flags |
| POST | /api/wifi |
Provision STA credentials; reboot on success |
| GET | /api/tuner/status |
Tuner snapshot (DAB/FM, RDS/DLS metadata) |
| GET | /api/tuner/services |
DAB service list for current ensemble |
| POST | /api/tuner/tune |
Tune DAB ensemble or FM frequency |
| POST | /api/tuner/play |
Start DAB service playback |
| POST | /api/tuner/seek |
FM seek up or down ({"direction":"up|down"}) |
| GET/PUT | /api/audio/profile |
Read/apply ADAU1701 mixer + 6-band EQ |
| POST | /api/audio/reset |
Factory-flat audio profile |
| POST | /api/audio/stereo-enhance |
Stereo depth overlay (0–100) |
| POST | /api/audio/bass-enhance |
Bass enhance overlay (0–100) |
| POST | /api/dsp/program |
Upload ADAU1701 DRAD blob (raw bytes, reboot) |
| POST | /api/system/ota |
Upload ESP32 firmware image (raw bytes, reboot) |
| GET | /api/bluetooth/status |
BT1035 boot, pairing, A2DP, name, auto-reconnect |
| GET | /api/bluetooth/paired |
Paired-device list from module |
| POST | /api/bluetooth/pair |
Enter discoverable mode |
| POST | /api/bluetooth/pair/stop |
Leave discoverable mode |
| POST | /api/bluetooth/disconnect |
Release A2DP session |
| POST | /api/bluetooth/auto-reconnect |
Set auto-reconnect count (0–15) |
| GET | /api/stations |
List saved presets |
| POST | /api/stations |
Add preset |
| POST | /api/stations/remove |
Remove preset by index |
| POST | /api/stations/reorder |
Move preset (from/to indices) |
| POST | /api/stations/tune |
Recall preset (tuner + audio profile + NVS) |
Wire schemas: docs/manual/ch-api.tex · C++ API:
doxygen Doxyfile → docs/api/html/index.html.
Layout
| Path | Role |
|---|---|
Firmware/ |
Si4684 .bin (local) + ADAU1701 SigmaStudio export |
components/core/ |
Pure domain (host-tested) |
components/drivers/ |
Si4684, ADAU1701, BT1035 |
components/services/ |
Tuner, audio, Bluetooth, station, integration |
components/secure_store/ |
Encrypted NVS: credentials, profiles, presets |
components/net/ |
Wi-Fi, HTTP server, gzipped web UI |
sdkconfig.defaults |
C++23, NVS + flash encryption (dev mode) |
partitions.csv |
nvs, otadata, dual OTA (ota_0/ota_1), dsp blob, nvs_keys |
docs/manual/ |
LaTeX technical manual |
docs/security-flash-nvs.md |
Encryption + device HIL checklist |
docs/TODO.md |
Completed tasks + HIL backlog |
tools/ |
Blob fetch, CI policy checks, UI gzip |
Manual PDF: cd docs/manual && latexmk -lualatex manual.tex
Licence
Apache-2.0 — see LICENSE.