b2b57fa39e01db6ffc39987191fc39e7b5481cb6
2
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Ashin Walpola
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0ccb867228 |
DENM over-the-air receive on the ESP32-C5 path
The firmware forwarded CAM only: gn_unwrap_cam accepted single-hop broadcast (HT=5) and BTP port 2001, so every DENM was dropped before it reached the phone. Real OBUs disseminate DENM by GeoBroadcast (HT=4), whose 44-byte extended header also carries the hazard's relevance area - materially more useful on a map than the sender's own position, since a sender may be relaying for someone else. Firmware - gn_unwrap_cam -> gn_unwrap_its: accepts GeoBroadcast alongside TSB/SHB, and BTP ports 2001 and 2002, extracting the GeoBroadcast destination area. Both extended-header lengths were measured against live air capture rather than read off a spec table. Secured packets (Basic Header NextHeader=2) are rejected rather than misparsed. - SERIAL_MSG_CAM_RX (0x02) superseded by SERIAL_MSG_V2X_RX (0x04): a 14-byte prefix carrying BTP port, RSSI and the destination area. Adding MAPEM later needs a decoder on the phone but no protocol change. 0x02 stays reserved so the numbering is not silently reused. - Promiscuous RX capture buffer 400 -> 800 bytes. A real GeoBroadcast DENM is around 500 bytes on air and was being truncated mid-payload, which no amount of correct unwrapping downstream could have recovered from. - geonet_wrap_shb, both firmwares: the SHB extended header is 28 bytes, not 24. The Source Position Vector is followed by a 4-byte reserved field; without it a standards-strict receiver reads the CAM payload's first two bytes as the BTP destination port. App - DenmUperCodec: UPER decoder for the ManagementContainer and the SituationContainer's eventType. ValidityDuration is 17 bits, not 16, and ManagementContainer, SituationContainer and CauseCode each carry their own extension bit - a single wrong bit made a real frame read causeCode 47 instead of 94. - DenmEvent gains actionID (originatingStationID + sequenceNumber), stationType, termination, detectionTime, relevance radius and RSSI. Dedup keys on actionID where available, so a termination lands on the event it ends instead of creating a second pin. - denmEvents merges the MQTT and over-the-air sources and drops terminated events. The V2X list view now shows hazards above the CAM stations; it previously took no DENM parameter at all, so hazards reached the map but never the list. - DenmParser: the Use Case API sends causeCode as a string enum, so reading it as an Int always yielded null. Testing - DenmAirReceiveTest covers the V2X_RX prefix and the decoder using real frames from a live capture as fixtures. Expected values were cross-checked against the ETSI ASN.1 modules via asn1tools, which agreed on all 1885 decodable DENMs across the capture set, every field including detectionTime. - Verified on hardware: a CiT One HLN-SV DENM decodes as cause 94/0 with a 1000 m relevance radius at 1 Hz alongside CAM, with no decode failures and no unexpected BTP ports. Also replaces em dashes with hyphens throughout the user-facing strings, including the German translation. |
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Ashin Walpola
|
f507a8a9fd |
Fix UPER encoding of CurvatureCalculationMode; verified on hardware
CurvatureCalculationMode is the one extensible ENUMERATED in CAM:
ENUMERATED {yawRateUsed(0), yawRateNotUsed(1), unavailable(2), ...}
UPER encodes an extensible ENUMERATED as an extension bit followed by the root
index - 1 + 2 = 3 bits. All three of our encoders wrote only the 2-bit index,
shifting yawRate and the entire low-frequency container one bit early for any
standards-compliant receiver.
It went unnoticed because every end of this project shared the mistake: the
Kotlin codec was ported bit-for-bit from cam.c, so phone and ESP32 agreed
perfectly with each other and with nothing else. Confirmed against the ETSI
ASN.1 in the C-ITS-Parser checkout, where rasn marks this type - and only this
type - #[non_exhaustive].
Fixed in all three copies of the encoder (app CamUperCodec.kt,
obu-firmware/main/cam.c, obu-cam-transmistter/main/cam.c) plus the decoder,
which now rejects rather than misreads a set extension bit. Frame size is
unchanged at 43 bytes. Transmitter reflashed and the phone decodes its CAMs.
Also in this change:
- serial_link: skip send_frame entirely when no USB host is attached, and raise
the tx mutex timeout above the worst-case hold. With the phone unplugged every
write blocked its full timeout while holding the lock, so forwarded CAM_RX
traffic starved the 1 Hz heartbeat - observed as "tx mutex timeout, dropping
frame" on the console, and it would have tripped the phone's link watchdog.
Verified gone on hardware.
- Log decoded and failed CAMs in CamUseCaseRepository. "The app shows nothing"
had two indistinguishable causes; a silent `?: return` made this bug much
harder to find than it needed to be.
- Remove the ESP32 send-only/send-and-receive toggle. Reception can't be
disabled in firmware (raw TX only works while promiscuous), so it was an
app-side filter pretending to be a radio control.
- V2X monitor follows the serial link state on the ESP32 path instead of MQTT,
which is permanently disconnected there; CAM intake is gated on the link being
up, and engine state is cleared when it drops.
- About screen: 0.5.0, Phase 03.
- Track obu-cam-transmistter, the bench CAM transmitter. Its cam.c is compiled
(unlike obu-firmware's reference copy) and must stay bit-identical to the other
two - this commit is what that coupling costs when it's broken.
- Document the two-toolchain split: this project builds on IDF 5.5.4, obu-firmware
on the pinned 6.1. Exporting both in one shell fails confusingly.
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