The BT-off custom slave (2.12.12) can't survive the C6's OTA rollback
protection: it flashes, the C6 boots it, reverts to 2.12.11, host
reflashes -> ~30s reboot loop, worse than the wedge. BLE-coex
hypothesis is UNTESTABLE via OTA (custom slaves won't stick; needs
direct C6 UART flash, out of scope tonight). Reverted to the
self-healing 2.12.11 baseline: ~5-13min MTBF, 15s auto-recovery.
That is the shippable overnight state.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The wedge clock is immune to every network-layer change (~300s
regardless of bus width, clock, power-save, DHCP). A slave-side
periodic starver remains; the C6's BLE controller (BT_LE_SLEEP_ENABLE=y
in stock slave, shares the radio/RF arbiter with Wi-Fi) is the prime
suspect. DeskLock uses no Bluetooth, so the stock slave carries a
coexistence scheduler we can delete outright. Custom slave 2.12.12
(CONFIG_BT_ENABLED=n, ESP_HOSTED_CP_BT=n), OTA'd over SDIO. If the
metronome stops, BLE coexistence was starving the SDIO peripheral.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Root cause of the dead data path (assoc/scan/RPC fine, zero data
frames): esp-hosted 1.4.x is formally incompatible with IDF 5.5
(esp-hosted-mcu#47) and the factory C6 slave firmware was ancient
(couldn't even answer a version RPC). Waveshare's examples pin 1.4.* —
do not follow them.
Fix:
- host: espressif/esp_hosted ^2.12 (+ esp_wifi_remote 1.6)
- slave: 2.12.11 network_adapter.bin embedded in the app (c6_ota.c
streams it to the C6 over the SDIO RPC channel at boot when the
reported version is < 2.x; ~10s, no wires, idempotent)
- RAM diet for hosted 2.x's footprint (MEMPOOL_PREFER_SPIRAM,
reduced WIFI_RMT buffers) — without it internal SRAM famine
boot-loops in xTaskCreateStaticPinnedToCore before app_main
- conservative 20MHz SDIO clock for first verified data path
Verified on hardware: DHCP lease (even that healed), 8/8 pings to
router and tower-of-joy at 1-5ms, WebSocket to the gateway connected,
device registered at /devices as desklock-p4 with fw version.
Also: wifi_diag.c L1 SoftAP diagnostic mode (DESKLOCK-DIAG) with
review fixes, boot ping ladder in net.c, static-IP fallback,
face_status() line, docs for the whole failure taxonomy.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>