micheleandCursor
0a1188ad66
Switch BT1035 bring-up from Line-In to I2S slave (AT+AUXCFG=3, AT+I2SCFG=67) to match the ADAU1701 PCM routing, confirm 2 kΩ I2C pull-ups on R1/R16, and sync firmware docs, AGENTS rules, and the DATASHEET bundle. Co-authored-by: Cursor <cursoragent@cursor.com>
269 lines
12 KiB
Markdown
269 lines
12 KiB
Markdown
<div align="center">
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# DigiRadio
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### DAB+/FM Bluetooth Receiver with SigmaDSP Audio Processing
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**Open-source digital radio — Si4684 tuner · ADAU1701 SigmaDSP · Bluetooth aptX Adaptive · ESP32-S3**
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[](Software/LICENSE)
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</div>
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---
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## Overview
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**DigiRadio** is an open-source digital radio receiver that combines terrestrial
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broadcast reception (**DAB+ / DAB / FM**) with a programmable audio-processing
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stage and high-quality **Bluetooth** audio output.
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Incoming broadcast audio is decoded by a Silicon Labs **Si4684** digital-radio
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receiver, processed by an Analog Devices **ADAU1701 SigmaDSP** (equalisation,
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mixing, level control), and transmitted over Bluetooth by a Qualcomm QCC3056-based
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**Feasycom FSC-BT1035** module supporting the **aptX Adaptive** codec. An Espressif
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**ESP32-S3** acts as the host controller, orchestrating the three subsystems and
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providing Wi-Fi connectivity, encrypted credential storage, and a browser-based
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configuration UI.
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The entire tuner → DSP → Bluetooth path is **fully digital (I²S, 48 kHz / 24-bit)** —
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no analogue conversions are introduced between the tuner and the wireless link.
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```
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FM/DAB antenna → [ Si4684 ] --I²S--> [ ADAU1701 DSP ] --I²S--> [ FSC-BT1035 ] → aptX
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↑ ↑ ↑
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└──── SPI ──── [ ESP32-S3 host ] ──── UART ────┘
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│ I²C
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Wi-Fi · NVS · HTTP UI
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```
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---
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## Key Features
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### Hardware
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- **DAB+ / DAB / FM** reception (Si4684) via external whip antenna (SMA)
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- **Fully digital audio path** — no avoidable A/D–D/A conversions
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- **Programmable audio processing** on the ADAU1701 SigmaDSP
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- **Bluetooth 5.2** output with **aptX / aptX HD / aptX Adaptive**
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- **ESP32-S3** host with native USB, Wi-Fi and BLE
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- **USB-C powered**; single-rail 3.3 V + low-noise 1.8 V for the tuner
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- **6-layer impedance-controlled PCB**, 50 × 90 mm, two ground planes
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- Three antennas (ESP32 2.4 GHz, BT1035 2.4 GHz, FM/DAB SMA) with proper keep-outs
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### Firmware (ESP-IDF, C++23 — fw **0.8.5**)
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| Area | Capability |
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|------|------------|
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| **Boot & chips** | Si4684 DAB+FM firmware load (HOST_LOAD blobs), ADAU1701 RAM program at every boot, BT1035 I2S slave init (`AT+AUXCFG=3`, `AT+I2SCFG=67`) |
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| **Tuner** | FM tune/seek, DAB ensemble tune, service scan & play, RSQ/RDS, DAB event status |
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| **Now playing** | FM RDS (PS, RadioText, PI, PTY) and DAB Dynamic Label (DLS) in status JSON and web UI |
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| **Audio** | 6-band EQ, input mixer, stereo/bass enhancement overlays, profile persist in encrypted NVS |
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| **Presets** | Station list CRUD, reorder, recall with audio profile re-apply, last-preset restore at boot |
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| **Bluetooth** | Discoverable pairing, A2DP status, disconnect |
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| **Network** | SoftAP setup mode, STA provisioning, tabbed gzipped SPA (`/`), typed JSON REST API |
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| **Security** | NVS + flash encryption at rest (dev mode); keys never in repo |
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| **Quality** | **13** host unit tests, 4 CI jobs (tests, Doxygen, manual sync, blob policy) |
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Architecture follows a **functional core + imperative shell**: pure domain logic
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(compilation, JSON, EQ design, RDS/DLS parsing) runs on the host under `ctest`;
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drivers and FreeRTOS live in thin ESP-IDF components. See [`Software/AGENTS.md`](Software/AGENTS.md).
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---
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## Firmware Progress
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Vertical slices landed on `main` (newest first):
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| Version | Highlights |
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|---------|------------|
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| **0.8.5** | BT1035 I2S slave boot init (schematic-aligned); I2C pull-ups R1/R16 confirmed 2 kΩ; `Hardware/DATASHEET/` bundle |
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| **0.8.4** | Dual OTA + DSP blob updates, EEPROM identity, System tab OTA/DSP upload |
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| **0.8.3** | NVS + flash encryption (development mode), `initEncryptedStorage`, security docs |
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| **0.8.2** | Tabbed Web UI (now-playing, 6-band EQ, all REST); Si4684 blob CI policy |
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| **0.8.1** | `IntegrationService` — boot preset recall, tune orchestration (tuner + audio + NVS `last_preset`); services stub removed |
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| **0.8.0** | Preset reorder API/UI; broadcast metadata (RDS + DAB DLS); `readDabServiceData` driver path |
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| **0.7.1** | CI workflow (host tests, Doxygen, manual sync); Doxygen warnings cleared |
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| **0.7.0** | Station presets (NVS `station_list`), BT1035 pairing, full `/api/stations/*` |
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| **0.5–0.6** | ADAU1701 runtime EQ/mixer, Si4684 tuning & DAB service list, BT1035 driver |
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| **0.3–0.4** | Secure store, Wi-Fi provisioning, companion-chip boot, walking skeleton |
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**Next:** device HIL when the PCB arrives ([`Software/docs/security-flash-nvs.md`](Software/docs/security-flash-nvs.md),
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[`Software/docs/TODO.md`](Software/docs/TODO.md)). Contributing:
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[`CONTRIBUTING.md`](CONTRIBUTING.md).
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---
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## Repository Structure
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```
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DigiRadio/
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├── .github/workflows/ CI — host tests, Doxygen, manual sync, Si4684 blob policy
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├── Hardware/
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│ ├── schematics/ Schematic (PDF)
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│ ├── gerber/ Gerber + drill (fabrication)
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│ ├── bom/ Bill of Materials
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│ ├── pick-and-place/ CPL / centroid
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│ ├── easyeda/ EasyEDA source
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│ └── 3d/ Renders / STEP
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├── Software/ Firmware project root — open this in Cursor
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│ ├── AGENTS.md Authoritative coding rules for agents
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│ ├── instructions.md Agent kickoff & slice roadmap
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│ ├── Doxyfile API documentation gate
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│ ├── components/
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│ │ ├── core/ Pure domain (host-tested, no ESP-IDF)
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│ │ ├── drivers/ Si4684, ADAU1701, BT1035
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│ │ ├── services/ Tuner, audio, Bluetooth, station, integration
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│ │ ├── secure_store/ NVS wrappers (Wi-Fi, profiles, presets)
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│ │ └── net/ Wi-Fi, HTTP server, gzipped web UI
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│ ├── docs/
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│ │ ├── manual/ LaTeX technical manual (canonical)
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│ │ ├── security-flash-nvs.md NVS/flash encryption + HIL checklist
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│ │ └── TODO.md Agent backlog and completed tasks
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│ ├── Firmware/ Si4684 blobs + ADAU1701 SigmaStudio export
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│ ├── main/ app_main, hardware bootstrap
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│ └── tools/ fetch_si4684_firmware, check_*, gzip-www
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├── CONTRIBUTING.md human-facing dev guide
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├── LICENSE CERN-OHL-S v2 (hardware)
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└── README.md ← you are here
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```
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Build the manual from `Software/docs/manual/`:
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```bash
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cd Software/docs/manual && latexmk -lualatex manual.tex
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```
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---
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## Getting Started
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### Firmware (developers)
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Open **`Software/`** as the Cursor project so `AGENTS.md` and `.cursor/rules/` load.
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```bash
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cd Software
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idf.py set-target esp32s3
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idf.py build
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idf.py erase-flash flash # once when first enabling encryption (0.8.3+)
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idf.py -p <port> monitor
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```
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Host unit tests (no hardware):
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```bash
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cd Software
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cmake -S components/core/test -B build-host \
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-DCMAKE_CXX_COMPILER="$(brew --prefix llvm)/bin/clang++" # macOS
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cmake --build build-host
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ctest --test-dir build-host --output-on-failure
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```
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Quality gates (also enforced in CI):
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```bash
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cd Software
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doxygen Doxyfile
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python3 tools/check-manual-sync.py
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python3 tools/check_si4684_blobs.py
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```
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Full build notes: [`Software/README.md`](Software/README.md) · security:
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[`Software/docs/security-flash-nvs.md`](Software/docs/security-flash-nvs.md).
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### First boot (device)
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1. Power the board; ESP32 starts **SoftAP** setup mode (`DigiRadio-setup` — see manual).
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2. Connect and open the gzipped web UI or call `GET /api/health`.
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3. `POST /api/wifi` with STA credentials; device reboots into normal mode.
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4. Tune via `/api/tuner/*`, manage presets via `/api/stations/*`, pair BT via `/api/bluetooth/*`.
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Schemas, error tokens, and boot flow: [`Software/docs/manual/ch-api.tex`](Software/docs/manual/ch-api.tex).
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---
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## HTTP API (summary)
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| Method | Path | Purpose |
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|--------|------|---------|
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| GET | `/api/health` | Status, firmware version, companion-chip flags |
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| POST | `/api/wifi` | Provision STA credentials |
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| GET | `/api/tuner/status` | Tuner snapshot incl. RDS/DLS metadata |
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| GET | `/api/tuner/services` | DAB service list |
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| POST | `/api/tuner/tune` · `/play` · `/seek` | Tuner control |
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| GET/PUT | `/api/audio/profile` | ADAU1701 mixer + EQ |
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| POST | `/api/audio/reset` · `/stereo-enhance` · `/bass-enhance` | Audio overlays |
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| GET | `/api/bluetooth/status` | BT1035 state |
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| POST | `/api/bluetooth/pair` · `/pair/stop` · `/disconnect` | Bluetooth control |
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| GET/POST | `/api/stations` · `/remove` · `/reorder` · `/tune` | Preset list & recall |
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Generated C++ API reference: run `doxygen Doxyfile` → `Software/docs/api/html/index.html`.
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---
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## Design Highlights
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| Topic | Choice | Rationale |
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|---|---|---|
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| **Audio quality** | QCC3056 / aptX Adaptive | Codec dominates wireless quality; DAC lives in the sink |
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| **Audio path** | Fully digital I²S | Avoids unnecessary A/D–D/A between tuner and Bluetooth |
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| **I²S master** | ADAU1701 (12.288 MHz) | Clean ×256 → 48 kHz; avoids sample-rate mismatch |
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| **Firmware style** | C++23, `std::expected`, RAII | Typed errors, host-testable core, no primitive obsession |
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| **Stack-up** | 6-layer, 2× GND | Solid ground under RF, crystals and USB |
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| **USB routing** | TOP, ref. GND | 90 Ω diff at manufacturable geometry |
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| **Antennas** | 3 zones, diagonal 2.4 GHz | Coexistence separation + full-layer keep-outs |
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---
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## Status
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| Layer | State |
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|-------|--------|
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| **Schematic** | Complete and reviewed |
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| **PCB layout** | 6-layer, DRC clean, plane continuity verified |
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| **BOM** | Finalised (manufacturable / sourced) |
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| **Prototype** | In fabrication (PCBWay) |
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| **Firmware** | **0.8.5** on `main` — BT1035 I2S boot init, dual OTA, encrypted NVS, full Web UI |
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| **Web UI** | Tabbed SPA covering every REST endpoint |
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| **HIL** | Device validation pending PCB (`Software/docs/security-flash-nvs.md`) |
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| **Agent backlog** | Feature-complete on `main` (fw 0.8.5); see [`Software/docs/TODO.md`](Software/docs/TODO.md) |
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---
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## Manufacturing
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The board is manufactured with **PCBWay** as a 6-layer, impedance-controlled PCB
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with turnkey assembly. The FSC-BT1035 Bluetooth module is sourced from Feasycom
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(the footprint uses a BT806-compatible, pin-identical land pattern). Component
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datasheets for design review live in
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[`Hardware/DATASHEET/`](Hardware/DATASHEET/) (Si4684-A10, AN851, ADAU1701, FSC-BT1035).
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See the [Technical Manual](Software/docs/manual/manual.tex) hardware chapter
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and manufacturing notes for fabrication settings and MSL-3 handling of the BT
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module.
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---
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## License
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- **Hardware** (schematics, PCB, Gerbers, BOM): CERN-OHL-S v2 — see [`LICENSE`](LICENSE)
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- **Firmware / Software**: Apache-2.0 — see [`Software/LICENSE`](Software/LICENSE)
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- **Documentation**: CC BY 4.0
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Intellectual property of the design remains with the author. You are free to study,
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modify and build the hardware under the terms of the respective licenses.
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---
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## Author
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**Michele Bigi** — Open-source hardware project.
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*Contributions, issues and questions are welcome via the [issue tracker](https://github.com/manvalan/DigiRadio/issues).*
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