SPATEM receive, RSU CAM decode, and two ASN.1 encoding fixes

SPATEM over the air - gn_unwrap.c accepts BTP-B port 2004 alongside 2001/2002. The serial protocol already carries the port in its V2X_RX prefix, so nothing else changed there. Note the crossover that makes this easy to get wrong: SPATEM is port 2004 but messageID 4, while MAPEM is port 2003 and messageID 5. - SpatemUperCodec decodes SPAT down to per-signal-group phase and timing. The bit layout was validated by replaying 79,042 real SPATEMs - the whole 2026-03-18 drive across 7+ RSUs plus the bench trigger - against asn1tools using the ETSI modules. All 79,042 matched on every field, none hit an unsupported branch. Two traps are pinned by tests: TimeChangeDetails is the one SEQUENCE here that is NOT extensible (5 optional bits, no extension bit), and maneuverAssistList cannot be skipped when present - it is variable-length, so it has to be walked to find where the next movement starts. - The V2X list shows one row per intersection with each signal group coloured by phase and a countdown where the RSU supplies timing. TimeMark wraps hourly, so the countdown corrects for it; without that it reads hugely negative once an hour, precisely when someone is watching it. - Entries expire after 15 s, much shorter than DENM's window: a traffic light that stopped updating is not "still green". Size caveat, deliberately deferred: SERIAL_LINK_MAX_PAYLOAD is still 512, so a SPATEM over ~498 bytes is counted as an oversize drop. The bench RSU sends 58 bytes and is unaffected, but real road RSUs measured 555 median / 1243 max, so roughly 70% would not arrive. Raising the cap also requires enlarging RX_FRAME_MAX_LEN and moving rx_item_t off the WiFi driver's callback stack, where it would otherwise overflow. RSU CAM decode - HighFrequencyContainer is a CHOICE, and a roadside unit picks rsuContainerHighFrequency, which carries no kinematics at all. The decoder bailed on that branch, so every RSU CAM was dropped - including the bench RSU, which sends CAM and SPATEM from the same station id. It now decodes for position and stationType. - RSU CAMs are kept out of UseCaseDetectionEngine. They arrive as a permanently stationary station at a fixed point, which is exactly the shape the stopped-vehicle and intersection-movement use cases match, and would raise a standing false alert for as long as the RSU was in range. CAM transmit: yawRateConfidence - YawRateConfidence has nine enumerands (0..8), so UPER needs 4 bits and "unavailable" is 8. The encoder wrote 3 bits with value 7 - one bit short and the wrong symbol - shifting every field after yawRate for any standards-strict receiver. The decoder read 3 bits too, so phone and ESP32 agreed with each other and with nothing else. - This is the third instance of that exact failure mode in this project, after CurvatureCalculationMode and the GeoNetworking reserved bytes. A round-trip test through our own decoder structurally cannot catch it, so CamEncodeGolden Test asserts the bytes asn1tools produces instead: it decoded this encoder's output and re-encoded it byte-identically. Confirmed on air afterwards - 26 of our own CAMs captured back off the OBU's receiver, all 26 accepted, where the same decoder rejected them before. DENM - Hazards now expire 60 s after their last repetition. This needs a clock, not just a filter: both source flows only emit when a DENM arrives, so a sender that drives away or loses power would never trigger a recompute and its hazard would stay on screen indefinitely. - The MQTT path was dropping every DENM for two independent reasons, both found by checking the payload against CI-CiT-MQTT_API_Documentation-v6 listing 2.6 rather than guessing: the station id key is originatingStationId, and eventPosition IS a GeoJSON Point rather than an object containing one. Also parses termination (presence is the signal), sequenceNumber, stationType and the RFC3339 detectionTime. Note roadSideUnit is 15, not 12 - the enumeration has a gap after tram(11). V2X screen - The decoded CAM/DENM list now renders on the CiT One path too; it was gated to the ESP32-C5 path and CiT One fell through to the raw MQTT topic list. Those topics move to their own tab, hidden on the ESP32-C5 path where there is no broker. Testing - Adds org.json as a test-only dependency: the android.jar stub throws "not mocked" on every JSONObject call, which made the MQTT payload parsers untestable off-device. - 23 V2X tests pass. EventDetectorTest's 4 failures are pre-existing and untouched by this change.
2026-08-20 15:47:14 +02:00
parent 0ccb867228
commit a5ad3dcc5d
20 changed files with 1159 additions and 52 deletions
@@ -33,6 +33,10 @@

 #define BTP_DEST_PORT_CAM           (2001) // ETSI TS 103 248
 #define BTP_DEST_PORT_DENM          (2002)
+// NOTE the crossover: SPATEM is BTP port 2004 but ItsPduHeader messageID 4, while MAPEM is port
+// 2003 and messageID 5. Port and messageID are NOT the same number - mixing them up routes every
+// message to the wrong decoder on the phone.
+#define BTP_DEST_PORT_SPATEM        (2004)

 static const uint8_t s_llc_snap_prefix[6] = {0xAA, 0xAA, 0x03, 0x00, 0x00, 0x00};

@@ -138,7 +142,8 @@ bool gn_unwrap_its(const uint8_t *frame, int frame_len, gn_rx_t *out)
        return false;
    }
    uint16_t dest_port = be16(frame + offset);
-    if (dest_port != BTP_DEST_PORT_CAM && dest_port != BTP_DEST_PORT_DENM) {
+    if (dest_port != BTP_DEST_PORT_CAM && dest_port != BTP_DEST_PORT_DENM &&
+        dest_port != BTP_DEST_PORT_SPATEM) {
        return false;
    }
    offset += BTP_B_HEADER_LEN;
@@ -29,11 +29,18 @@
 // talks to sends them, and each has its own extended-header length that would need measuring.
 //
 // ---- Accepted BTP-B ports (ETSI TS 103 248) ------------------------------------------------
-// 2001 (CAM) and 2002 (DENM). MAPEM (2003), SPATEM (2004) and the rest are deliberately not
+// 2001 (CAM), 2002 (DENM) and 2004 (SPATEM). MAPEM (2003) and the rest are deliberately not
 // accepted yet: the phone has no decoder for them, so forwarding would just burn serial
 // bandwidth. Adding one is a one-line change here plus a decoder on the phone - the serial
 // protocol itself is already generic (see SERIAL_MSG_V2X_RX in serial_link.h).
 //
+// SPATEM size caveat: SERIAL_LINK_MAX_PAYLOAD is 512, so a SPATEM whose UPER exceeds 498 bytes is
+// counted as an oversize drop rather than forwarded. The bench RSU trigger emits ~58-byte SPATEMs
+// and is unaffected, but real road RSUs measured 555 bytes median and 1243 max (2026-03-18 drive,
+// 79k messages), i.e. roughly 70% would be dropped. Raising the cap is deliberately deferred: it
+// also requires enlarging RX_FRAME_MAX_LEN and moving rx_item_t off the WiFi callback stack,
+// which at that size would overflow it.
+//
 // ---- What is NOT handled -------------------------------------------------------------------
 // Secured packets (GN Basic Header NextHeader=2, i.e. ETSI TS 103 097 signed messages). The
 // units on this bench run with ItsGnSecurity=0 so everything observed is unsecured; a secured