After 5 systematic experiments confirmed the 802.15.4 RX path is
unfixable from user code in this IDF v5.4 + C6 combination (D1), add a
parallel sync transport over ESP-NOW. Same TS_BEACON protocol, same
public API (c6_sync_espnow_get_epoch_us / is_valid / is_leader), but
runs on the WiFi MAC layer that ESP-IDF fully supports across every
ESP32 family.
The 802.15.4 code stays in source for when the IDF driver is fixed.
ESP-NOW is the working primary today.
Empirical (single-board COM9 — other 3 boards dropped off USB during
the experiment):
- c6_sync_espnow_init() succeeds: "init done local_id=… leader=
yes(candidate) period=100ms"
- TX path 100% reliable: tx#101 fail=0 over ~15s at 100ms cadence
- RX awaiting cross-board test once USB-enumeration is restored
Trade vs. 802.15.4 design:
- Loses: "frees WiFi airtime for CSI" property
- Gains: known-working RX path, cross-target (S3 and C6 both)
- Same API surface — consumers swap transports without code change
Files:
- main/c6_sync_espnow.{h,c} — new module, ~210 lines
- main/CMakeLists.txt — add to SRCS (always built, used on any target)
- main/main.c — init after WiFi STA up, skip on QEMU mock
- test/capture-3board-experiment.py — surface c6_espnow log lines
- docs/WITNESS-LOG-110.md — new §D-workaround documenting the pivot
Ref: ruvnet/RuView#762 / D1 known-issue / draft PR #764
Co-Authored-By: claude-flow <ruv@ruv.net>
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