# Dante / AES67 Audio-over-IP for ESP32-P4

**Status: planning / architecture phase — no firmware written yet.**

## Goal

A low-cost, network audio endpoint on the ESP32-P4 that can interoperate with
Dante-based AV systems. In practice "Dante-interoperable" is being pursued in
two phases:

1. **AES67 interop (primary target)** — most Dante hardware from the last
   several years can send/receive AES67, so a solid AES67 endpoint already
   gets us into the same audio network as Dante gear.
2. **Native Dante protocol support (stretch goal)** — Dante's proprietary
   discovery (mDNS records), control protocol (routing/subscription), and
   PTPv1 clocking, for talking to older or AES67-disabled Dante devices.

## Why ESP32-P4

The original ESP32 (WiFi, Xtensa) can't hold AES67's ~1ms RTP packet timing
tightly enough over WiFi to be spec-compliant. The P4 drops WiFi in favour of
a real Ethernet MAC with hardware PTP timestamping, which is what makes
sub-millisecond, spec-accurate AoIP achievable on this class of chip at all.

## Two source projects this builds on

### 1. [DatanoiseTV/aes67-esp32p4](https://github.com/DatanoiseTV/aes67-esp32p4) — foundation (Apache-2.0)

This is what we fork from. It already solves the hard, P4-specific problems:
hardware PTP timestamping via the EMAC, an I2S driver with APLL clock
recovery, an RTP engine with an L2 hook that bypasses lwIP for latency,
SAP/SDP, and mDNS/DNS-SD advertisement. Apache-2.0 means we can build on it
freely, including for commercial client work.

### 2. [teodly/inferno](https://github.com/teodly/inferno) — protocol reference only (GPL-3.0-or-later / AGPL-3.0-or-later)

A full software Dante device implementation for Linux. **We do not vendor or
copy code from this repo.** It's copyleft-licensed, and incorporating its
code would obligate this whole firmware image to the same license — which
rules out using it in closed commercial deliverables. Instead it's used as
documentation: reading `inferno_aoip` to understand Dante's wire behaviour
(mDNS service records, control-protocol framing, flow subscriptions) well
enough to write an independent, clean-room implementation against the P4
component.

> **This licensing boundary is the most important constraint on this
> project.** See `CLAUDE.md` for the hard rule any dev session (human or
> agent) needs to follow.

## Hardware target

Starting point is DatanoiseTV's reference pinout for the **ESP32-P4-NANO**
board — confirm/update against whatever board this actually gets deployed on:

| Function | GPIO | Notes |
|---|---|---|
| Ethernet MDC | 31 | |
| Ethernet MDIO | 52 | |
| Ethernet REF_CLK | 50 | External 50MHz crystal |
| Ethernet PHY_RST | 51 | |
| I2S MCLK | 13 | 18.432MHz via APLL |
| I2S BCLK | 36 | (onboard: 12) |
| I2S LRCLK | 33 | (onboard: 10) |
| I2S DOUT | 32 | (onboard: 9) |
| I2S DIN | 11 | Codec ADC input |
| PA Enable | 53 | Active high |
| I2C SCL / SDA | 8 / 7 | ES8311 control |

Ethernet PHY: IP101 GRI via RMII. Onboard codec: ES8311 + NS4150B amp.

## Repo layout

```
components/aes67/   Forked from aes67-esp32p4 — AES67 engine (PTP, RTP, I2S, SAP/SDP, mDNS)
main/                Application entry point, board config
docs/                Design notes, incl. clean-room Dante protocol notes
reference/           Local clones of both source repos, for reading only (gitignored, not part of this repo)
```

## Build

Requires ESP-IDF v5.5+ with the ESP32-P4 target.

```bash
idf.py set-target esp32p4
idf.py build
idf.py flash monitor
```

(Not yet functional — `components/aes67` hasn't been forked in yet.)

## Roadmap

- [ ] Fork `aes67-esp32p4`'s `components/aes67` in as the starting point
- [ ] Confirm pinout against actual target hardware
- [ ] Get AES67 send/receive verified against real Dante gear in AES67 mode
- [ ] Write clean-room Dante protocol notes (`docs/dante-protocol-notes.md`)
- [ ] Prototype Dante mDNS advertisement/discovery
- [ ] Prototype Dante control protocol (routing/subscriptions)
- [ ] Investigate PTPv1 support alongside the existing PTPv2 stack

## License

Apache-2.0 (see `LICENSE`), matching the `aes67-esp32p4` base this project
forks from.