# P6: homeai-esp32 — Room Satellite Hardware

> Phase 4 | Depends on: P1 (HA running), P3 (Wyoming STT/TTS servers running)

---

## Goal

Flash ESP32-S3-BOX-3 units with ESPHome. Each unit acts as a dumb room satellite: always-on mic, on-device wake word detection, audio playback, and a display showing assistant state via static PNG face illustrations. All intelligence stays on the Mac Mini.

---

## Hardware: ESP32-S3-BOX-3

| Feature | Spec |
|---|---|
| SoC | ESP32-S3 (dual-core Xtensa, 240MHz) |
| RAM | 512KB SRAM + 16MB PSRAM |
| Flash | 16MB |
| Display | 2.4" IPS LCD, 320×240, touchscreen (ILI9xxx, model S3BOX) |
| Audio ADC | ES7210 (dual mic array, 16kHz 16-bit) |
| Audio DAC | ES8311 (speaker output, 48kHz 16-bit) |
| Speaker | Built-in 1W |
| Connectivity | WiFi 802.11b/g/n (2.4GHz only), BT 5.0 |
| USB | USB-C (programming + power, native USB JTAG serial) |

---

## Architecture Per Unit

```
ESP32-S3-BOX-3
├── micro_wake_word (on-device, always listening)
│   └── "hey_jarvis" — triggers voice_assistant on wake detection
├── voice_assistant (ESPHome component)
│   ├── connects to Home Assistant via ESPHome API
│   ├── HA routes audio → Mac Mini Wyoming STT (10.0.0.101:10300)
│   ├── HA routes text → OpenClaw conversation agent (10.0.0.101:8081)
│   └── HA routes response → Mac Mini Wyoming TTS (10.0.0.101:10301)
├── Display (ili9xxx, model S3BOX, 320×240)
│   └── static PNG faces per state (idle, listening, thinking, replying, error)
└── ESPHome OTA
    └── firmware updates over WiFi
```

---

## Pin Map (ESP32-S3-BOX-3)

| Function | Pin(s) | Notes |
|---|---|---|
| I2S LRCLK | GPIO45 | strapping pin — warning ignored |
| I2S BCLK | GPIO17 | |
| I2S MCLK | GPIO2 | |
| I2S DIN (mic) | GPIO16 | ES7210 ADC input |
| I2S DOUT (speaker) | GPIO15 | ES8311 DAC output |
| Speaker enable | GPIO46 | strapping pin — warning ignored |
| I2C SCL | GPIO18 | audio codec control bus |
| I2C SDA | GPIO8 | audio codec control bus |
| SPI CLK (display) | GPIO7 | |
| SPI MOSI (display) | GPIO6 | |
| Display CS | GPIO5 | |
| Display DC | GPIO4 | |
| Display Reset | GPIO48 | inverted |
| Backlight | GPIO47 | LEDC PWM |
| Left top button | GPIO0 | strapping pin — mute toggle / factory reset |
| Sensor dock I2C SCL | GPIO40 | sensor bus (AHT-30, AT581x radar) |
| Sensor dock I2C SDA | GPIO41 | sensor bus (AHT-30, AT581x radar) |
| Radar presence output | GPIO21 | AT581x digital detection pin |

---

## ESPHome Configuration

### Platform & Framework

```yaml
esp32:
  board: esp32s3box
  flash_size: 16MB
  cpu_frequency: 240MHz
  framework:
    type: esp-idf
    sdkconfig_options:
      CONFIG_ESP32S3_DEFAULT_CPU_FREQ_240: "y"
      CONFIG_ESP32S3_DATA_CACHE_64KB: "y"
      CONFIG_ESP32S3_DATA_CACHE_LINE_64B: "y"

psram:
  mode: octal
  speed: 80MHz
```

### Audio Stack

Uses `i2s_audio` platform with external ADC/DAC codec chips:

- **Microphone**: ES7210 ADC via I2S, 16kHz 16-bit mono
- **Speaker**: ES8311 DAC via I2S, 48kHz 16-bit mono (left channel)
- **Media player**: wraps speaker with volume control (min 50%, max 85%)

### Wake Word

On-device `micro_wake_word` component with `hey_jarvis` model. Can optionally be switched to Home Assistant streaming wake word via a selector entity.

### Display

`ili9xxx` platform with model `S3BOX`. Uses `update_interval: never` — display updates are triggered by scripts on voice assistant state changes. Static 320×240 PNG images for each state are compiled into firmware. No text overlays — voice-only interaction.

Screen auto-dims after a configurable idle timeout (default 1 min, adjustable 1–60 min via HA entity). Wakes on voice activity or radar presence detection.

### Sensor Dock (ESP32-S3-BOX-3-SENSOR)

Optional accessory dock connected via secondary I2C bus (GPIO40/41, 100kHz):

- **AHT-30** (temp/humidity) — `aht10` component with variant AHT20, 30s update interval
- **AT581x mmWave radar** — presence detection via GPIO21, I2C for settings config
- **Radar RF switch** — toggle radar on/off from HA
- Radar configured on boot: sensing_distance=600, trigger_keep=5s, hw_frontend_reset=true

### Voice Assistant

ESPHome's `voice_assistant` component connects to HA via the ESPHome native API (not directly to Wyoming). HA orchestrates the pipeline:
1. Audio → Wyoming STT (Mac Mini) → text
2. Text → OpenClaw conversation agent → response
3. Response → Wyoming TTS (Mac Mini) → audio back to ESP32

---

## Directory Layout

```
homeai-esp32/
├── PLAN.md
├── setup.sh                          # env check + flash/ota/logs commands
└── esphome/
    ├── secrets.yaml                  # gitignored — WiFi + API key
    ├── homeai-living-room.yaml       # first unit (full config)
    ├── homeai-bedroom.yaml           # future: copy + change substitutions
    ├── homeai-kitchen.yaml           # future: copy + change substitutions
    └── illustrations/                # 320×240 PNG face images
        ├── idle.png
        ├── loading.png
        ├── listening.png
        ├── thinking.png
        ├── replying.png
        ├── error.png
        └── timer_finished.png
```

---

## ESPHome Environment

```bash
# Dedicated venv (Python 3.12) — do NOT share with voice/whisper venvs
~/homeai-esphome-env/bin/esphome version  # ESPHome 2026.2.4+

# Quick commands
cd ~/gitea/homeai/homeai-esp32
~/homeai-esphome-env/bin/esphome run esphome/homeai-living-room.yaml     # compile + flash
~/homeai-esphome-env/bin/esphome logs esphome/homeai-living-room.yaml    # stream logs

# Or use the setup script
./setup.sh flash    # compile + USB flash
./setup.sh ota      # compile + OTA update
./setup.sh logs     # stream device logs
./setup.sh validate # check YAML without compiling
```

---

## Wake Word Options

| Option | Latency | Privacy | Effort |
|---|---|---|---|
| `hey_jarvis` (built-in micro_wake_word) | ~200ms | On-device | Zero |
| Custom word (trained model) | ~200ms | On-device | High — requires 50+ recordings |
| HA streaming wake word | ~500ms | On Mac Mini | Medium — stream all audio |

**Current**: `hey_jarvis` on-device. Train a custom word (character's name) once finalised.

---

## Implementation Steps

- [x] Install ESPHome in `~/homeai-esphome-env` (Python 3.12)
- [x] Write `esphome/secrets.yaml` (gitignored)
- [x] Write `homeai-living-room.yaml` (based on official S3-BOX-3 reference config)
- [x] Generate placeholder face illustrations (7 PNGs, 320×240)
- [x] Write `setup.sh` with flash/ota/logs/validate commands
- [x] Write `deploy.sh` with OTA deploy, image management, multi-unit support
- [x] Flash first unit via USB (living room)
- [x] Verify unit appears in HA device list
- [x] Assign Wyoming voice pipeline to unit in HA
- [x] Test: speak wake word → transcription → LLM response → spoken reply
- [x] Test: display cycles through idle → listening → thinking → replying
- [x] Verify OTA update works: change config, deploy wirelessly
- [ ] Write config templates for remaining rooms (bedroom, kitchen)
- [ ] Flash remaining units, verify each works independently
- [ ] Document final MAC address → room name mapping

---

## Success Criteria

- [ ] Wake word "hey jarvis" triggers pipeline reliably from 3m distance
- [ ] STT transcription accuracy >90% for clear speech in quiet room
- [ ] TTS audio plays clearly through ESP32 speaker
- [ ] Display shows correct state for idle / listening / thinking / replying / error / muted
- [ ] OTA firmware updates work without USB cable
- [ ] Unit reconnects automatically after WiFi drop
- [ ] Unit survives power cycle and resumes normal operation

---

## Known Constraints

- **Memory**: voice_assistant + micro_wake_word + display + sensor dock is near the limit. Do NOT add Bluetooth or LVGL widgets — they will cause crashes.
- **WiFi**: 2.4GHz only. 5GHz networks are not supported.
- **Speaker**: 1W built-in. Volume capped at 85% to avoid distortion.
- **Display**: Static PNGs compiled into firmware. To change images, reflash via OTA (~1-2 min).
- **First compile**: Downloads ESP-IDF toolchain (~500MB), takes 5-10 minutes. Incremental builds are 1-2 minutes.