Files
DigiRadio/Software/instructions.md
T
micheleandCursor 81d404a1df Add Slice 4 tuner stack with AGENTS-compliant core types and HTTP API.
Introduces Si4684/ADAU1701 drivers, TunerService, FrequencyKHz,
SeekDirection, /api/tuner routes without file-scope globals, host tests,
and firmware blob tooling (binaries remain gitignored).

Co-authored-by: Cursor <cursoragent@cursor.com>
2026-07-06 16:17:56 +02:00

122 lines
5.4 KiB
Markdown

# instructions.md — DigiRadio firmware, agent kickoff
Read this together with `AGENTS.md` and everything under
`.cursor/rules/`. Those define *how* to write code; this file defines
*what we are building* and *what to do first*.
## What DigiRadio is
An open-source Hi-Fi DAB+/FM digital radio board. Firmware runs on an
ESP32-S3 and coordinates three companion chips:
- **Si4684** — DAB+/FM tuner (delivers the audio stream).
- **ADAU1701** — SigmaDSP: equaliser + input mixer between the Si4684
and the ESP32 audio path. Program is written to DSP RAM at every boot
(no self-boot EEPROM).
- **FSC-BT1035 (QCC3056)** — Bluetooth 5.2 out with aptX Adaptive,
controlled by AT commands over UART.
Plus: an elegant, essential web UI for network configuration; encrypted
storage for Wi-Fi and user credentials and the station list.
Repository: https://github.com/manvalan/DigiRadio
## Confirmed technical decisions (do not re-litigate)
| Area | Decision |
|-------------|-------------------------------------------------------|
| Framework | ESP-IDF v5.5.x (native, not Arduino) |
| Language | C++23, pinned `-std=gnu++23` |
| Errors | `std::expected<T, Error>` (native); exceptions OFF |
| DSP boot | ESP32 writes ADAU1701 RAM at every boot (no EEPROM) |
| Architecture| Functional core (pure, host-tested) + imperative shell|
| Docs | Doxygen, build must exit 0 (enforced) |
| HW licence | CERN-OHL-S v2 · FW licence: Apache-2.0 |
## Working agreement
- **Confirm understanding before writing code.** On kickoff, summarise
the plan and list any blockers or unclear hardware invariants first.
- **Blockers first**, always. State risks before solutions.
- **One vertical slice at a time.** `main` always builds and runs.
- Every file gets the Apache header; every class/method its doc block;
`doxygen Doxyfile` stays green. Small commits, 50/72 messages.
- Never invent a register/opcode/boot step — cite the datasheet or stop.
## Roadmap (slices, in order)
1. **Walking skeleton** — done (Slice 1).
2. **Secure store + Wi-Fi provisioning** — done (Slice 2).
3. **Companion-chip boot** — done (Slice 3): Si4684 DAB + ADAU1701 RAM load.
4. Station/frequency list model + persistence + UI.
5. Si4684 tuning: RSQ, station list, DAB properties.
6. ADAU1701 runtime: safeload EQ + input mixer.
7. FSC-BT1035 driver: AT init (incl. `AT+AUXCFG=1`), audio out.
8. Integration: TunerService + AudioService end to end.
## Slice 1 — Walking skeleton (complete)
Goal: exercise the whole toolchain end to end with zero chip hardware,
so every later slice drops into a working frame.
Build:
- Top-level ESP-IDF project targeting `esp32s3`.
- `sdkconfig.defaults` sets C++23, exceptions off, and documents flash/NVS
encryption options (not hard-enabled until production).
- The `components/core` component compiles both under ESP-IDF and
standalone on the host.
Behaviour:
- `app_main` starts a FreeRTOS task that logs a heartbeat on a timer.
- Bring up SoftAP with a known SSID (e.g. `DigiRadio-setup`).
- Start an HTTP server serving one minimal gzipped page from flash.
- Expose `GET /api/health` returning a typed DTO serialised by the pure
core, e.g. `{"status":"ok","fw":"0.3.0"}`.
Documentation (required):
- Doxygen doc blocks on every class/method; `doxygen Doxyfile` green.
- Manual: class sections in `docs/manual/ch-classes.tex`;
HTTP API in `docs/manual/ch-api.tex`.
- `python3 tools/check-manual-sync.py` green.
## Slice 2 — Secure store + Wi-Fi STA (complete)
Goal: persist Wi-Fi credentials and join the configured network after
provisioning; fall back to SoftAP when no credentials or join fails.
Build on Slice 1:
- `core::ISecureStore` interface + `secure_store::NvsSecureStore` (NVS).
- `core::Secret`, `WifiSsid`, `WifiCredentials`, `parseWifiProvisionJson`.
- `net::StaClient`, `NetBootstrap::start(store)` state machine.
- `POST /api/wifi` + provisioning form in the web UI; reboot after save.
Acceptance criteria:
- [x] Provisioning via SoftAP saves credentials and reboots; next boot joins STA.
- [x] Host tests for health JSON and Wi-Fi provision parse/serialise.
- [x] Doxygen green; manual sync green; `ch-api.tex` documents endpoints.
- [x] No ESP-IDF headers in `components/core`.
Out of scope: station list, user credentials, NVS encryption enablement
(production), chip drivers.
## Slice 3 — Companion-chip boot (complete)
Goal: load Si4684 DAB firmware and ADAU1701 SigmaStudio program from
`Firmware/` on every boot, before network bring-up.
Build:
- `Firmware/Si4684-Firmware/``rom_patch_016.bin`, `dab_firmware.bin`,
`fm_firmware.bin` (FM via `tools/fetch_si4684_firmware.py --si46xx-dir`).
- `Firmware/ADAU1701-Firmware/` — SigmaStudio export (`DigiRadio_IC_1.h`, …).
- `core::IFirmwareBlobReader` + `EmbeddedBlobReader` for chunked HOST_LOAD.
- `si4684::Si4684Driver`, `adau1701::Adau1701Driver`, `HardwareBootstrap`.
Behaviour:
- `app_main` calls `HardwareBootstrap::boot()` first (Si4684, then ADAU1701).
- On failure, firmware logs and halts before Wi-Fi.
Acceptance criteria:
- [x] AN649 boot sequence with streaming blobs (no full image on heap).
- [x] ADAU1701 reset + I2C + `default_download_IC_1()` replay.
- [x] Host test for `EmbeddedBlobReader`; manual sync green.
- [ ] Device flash verified (requires ESP-IDF toolchain on build host).