Bug #2 (root cause): LD2410 probe-detection matched only the 4-byte head
0xF4F3F2F1, so a floating UART at 256000 baud could phantom-detect a sensor
and spawn a UART task. Now requires a full validated report frame (head +
sane length + tail 0xF8F7F6F5), extracted to mmwave_detect.h and shared with
a host unit test (test_mmwave_detect.c, 8 vectors) so firmware and test can't
diverge. Matches the validate-before-trust approach used for MR60 in #1107.
Bug #1: sendto ENOMEM used a fixed 100 ms backoff too short to drain sustained
lwIP/WiFi buffer pressure, so a node could stay stuck. Now exponential
(100->200->...->2000 ms per consecutive ENOMEM, reset on first successful
send). Removing the phantom LD2410 task (bug #2) also removes the extra load
that tipped the reporter's tier-2 node into the stuck state.
Validated on ESP32-S3 QFN56 rev v0.2 (the reporter's silicon): tier-2 streams
~100 frames/s with no stuck ENOMEM and correctly reports no mmWave (no
phantom). LD2410 predicate truth table proven (head-without-tail REJECTED).
Could not reproduce the reporter's environment-specific floating-pin noise, so
the deterministic proof is the host unit test.
probe_at_baud counted bare 0x01 (SOF) bytes and declared MR60BHA2 on a single one.
A floating UART1 with no sensor reads noise full of 0x01s → false 'Detected MR60BHA2
(caps=0x000f)'. Now a candidate must be a full 8-byte header with a valid header
checksum (bytes 0..6) AND a known frame type (0x0A__ / 0x0F09), and clear the ≥3
threshold; removed the weak single-hit fallback. Real sensors stream valid frames
continuously, so detection of present hardware is unaffected.
Co-authored-by: ruv <ruvnet@gmail.com>
rUv
OrbisAI Security