Root cause (verified against our exact IDF tree, not the community guess): the "258" in "sdio_write_task: Failed to send data: 258" is NOT a timeout (that is 263). 258 = 0x102 = ESP_ERR_INVALID_ARG. On the ESP32-P4, block- mode CMD53 writes require the SOURCE buffer to be 64-byte (cache-line) aligned; the IDF sdmmc driver rejects a misaligned source with INVALID_ARG BEFORE any bus activity. esp_hosts write loop then declares "Unrecoverable host sdio state" and reboots the whole P4. The audio TX payload is not 64-aligned, so streaming mic audio wedged on the very FIRST frame (which is exactly what we saw: listening -> instant Failed to send -> reboot). This also explains why buffer/queue/clock/retry tuning all did nothing: the write never reached the bus. And why our symptom was instant, not after ~100 writes (the community block-mode-desync theory) — it is the first misaligned buffer, every time. Fix: vendored esp_hosted 2.12.11 as an editable local component (overrides the registry copy) and bounce a misaligned TX payload through one aligned DMA scratch buffer in hosted_sdio_write_block (port_esp_hosted_host_sdio.c). TX is serialized by the bus lock so a single static bounce buffer is safe; freed in hosted_sdio_deinit. Host-only change — no C6 reflash. VERIFIED ON HARDWARE (autonomous self-test): 40s of continuous mic-audio upstream streaming — the traffic that previously wedged on the first frame — ran clean, zero timeouts, zero reboots. A guarded SDIO_TX_SELFTEST harness is kept (compiled out) for future SDIO stress testing. Credit: root cause + patch designed via multi-agent investigation; the precise 258=INVALID_ARG decode (correcting the upstream community timeout assumption) came from checking our actual esp_err.h. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
DeskLock
A living-room visual/audio endpoint for Tatlock, the homelab butler. DeskLock gives Tatlock a face and a voice on a Waveshare round touch display: you talk to it, it listens, thinks, and answers — the first line of contact with the butler backend running on tower-of-joy.
Hardware
Waveshare ESP32-P4-WIFI6-Touch-LCD-3.4C
| Component | Details |
|---|---|
| SoC | ESP32-P4NRW32 — dual-core RISC-V @ 400 MHz + LP core |
| Memory | 32 MB PSRAM (in-package), 32 MB NOR flash |
| Display | 3.4" round IPS, 800×800, MIPI-DSI 2-lane, capacitive touch |
| Radio | ESP32-C6-MINI-1 (Wi-Fi 6 + BLE 5) over SDIO via ESP-Hosted |
| Audio in | Dual onboard microphones + ES7210 echo-cancellation ADC |
| Audio out | ES8311 codec, PH2.0 2-pin speaker connector (8Ω 2W recommended) |
| Flashing | USB-C (hold BOOT during reset for download mode) |
The device is currently connected over USB-C directly to tower-of-joy, so build/flash happens on this server.
Architecture
┌──────────────────────┐ WebSocket: PCM audio + JSON events
│ DeskLock device │◄───────────────────────────────────┐
│ (ESP32-P4) │ │
│ • LVGL face │ ┌──────────────────────────────┴───────────┐
│ • touch / wake word │ │ DeskLock Gateway (container, :8600) │
│ • mic capture + AEC │ │ thin orchestrator — no ML dependencies │
│ • TTS playback │ └───────┬──────────────────┬───────────────┘
└──────────────────────┘ │ │ OpenAI-format HTTP
│ ▼
HTTP (LAN) │ ┌─────────────────────────────┐
▼ │ Speaches (container, GPU) │
┌────────────────────┐ │ • STT: faster-whisper │
│ Tatlock (butler) │ │ • TTS: Kokoro / Piper │
│ tatlock.schweitz. │ │ also usable by Open WebUI, │
│ internal :8000 │ │ Home Assistant, … │
└────────────────────┘ └─────────────────────────────┘
Tatlock stays a text-only brain. The gateway orchestrates speech-to-text, chat, and text-to-speech; the Speaches container owns the actual STT/TTS models on the GPU, shared homelab-wide. The device firmware stays thin: audio transport, wake word, and face rendering only. Everything runs on the LAN — no cloud in the voice path.
See docs/architecture.md for the full design.
Repository layout
firmware/— ESP-IDF (C, LVGL 9) application for the ESP32-P4gateway/— Python FastAPI voice gateway, deployed as a container on tower-of-joysim/face/— browser simulator of the face (design source of truth; serve withpython3 -m http.serverand openindex.html, or use?state=…&nochrome=1for screenshots)docs/— architecture and design notes
Roadmap
Bring-up✅ — display, touch, audio, 200 MHz PSRAM, cathedral gong- Face + voice loop (in hardware test) — full LVGL face (7 states, rain, orbit, power ladder), Wi-Fi, WebSocket, touch-to-talk
- Voice (touch-to-talk) — tap to talk → gateway → Tatlock → spoken reply
- Wake word — esp-sr WakeNet on-device, echo cancellation, barge-in
- Polish — Tatlock-initiated notifications, presence, OTA updates