Drive the ESP32-C5 station over USB or BLE, send CAM or VAM, signed or not

The app now speaks the station-link protocol of the new obu-firmware. Esp32Link picks the transport from Settings (UsbSerialTransport or the new BleLinkTransport), tells the previous firmware from the new one by its heartbeat, and runs the session: STATION_CONFIGURE with the current pseudonym MAC (which also starts the board's radio), CREDENTIALS_PROVISION of the bundled demo chain when the board has no ticket, then per message a POTI_UPDATE and a BTP_DATA_REQUEST. Received messages still arrive as V2X_RX frames, so the receive side is unchanged. A board on the previous firmware keeps working for CAM over USB. Settings > Connection > ESP32-C5: link USB-C or Bluetooth, transmit CAM or VAM, "Sign outgoing messages" (on by default). The connection card, top bar and dashboard show the link in use, the pairing passkey and signing counters. - VAM: VamUperCodec (TS 103 300-3 V2.3.1, bytes checked against asn1tools) and VamGenerationRules (clause 6.4, Tables 16/17). - BLE: the firmware's GATT layout (service 0000C175-...), MTU 517, pairing and encryption settled before any other operation (short timeouts during pairing made it loop), backoff between attempts, reasons on the card. - Clock: a PoTi goes to the board once per new fix and never moves the board's clock backwards except for a real correction (>= 60 s); stale and wobbling fix times made the board answer time_regression and restart its stack every few seconds. GnssTimeSource keeps the last measured phone-clock error while GNSS time drops out indoors: the bench phone is 14 minutes fast, and falling back to it made every transmitted timestamp jump by that much. - assets/demo-chain.vcr: throwaway, not EU-registered demo chain generated 2026-09-23 (AT B80B49387A4C12EB, psid 36 and 638). Its private key ships with the app on purpose; receivers verifying against the EU trust list drop what it signs. - Bluetooth permissions requested at start-up on Android 12+. StationLinkTest pins the codec to bytes from the colleague's Python implementation (microbu_link/messages.py). 103 unit tests pass.
2026-09-23 17:28:05 +02:00
parent d2fd222a62
commit a08494b56a
27 changed files with 2092 additions and 134 deletions
@@ -6,13 +6,18 @@ import com.hawhamburg.micr0bu.data.GnssTimeSource
 import com.hawhamburg.micr0bu.data.SensorRepository
 import com.hawhamburg.micr0bu.data.cam.PseudonymManager
 import com.hawhamburg.micr0bu.data.mqtt.ObuHardwarePreferences
+import com.hawhamburg.micr0bu.data.transport.Esp32Link
 import com.hawhamburg.micr0bu.data.transport.GnPositionVector
 import com.hawhamburg.micr0bu.data.transport.ObuHardware
-import com.hawhamburg.micr0bu.data.transport.UsbSerialTransport
+import com.hawhamburg.micr0bu.data.transport.OutgoingIts
+import com.hawhamburg.micr0bu.data.transport.OutgoingMessage
 import com.hawhamburg.micr0bu.domain.asn1.RealAsn1UperCodec
+import com.hawhamburg.micr0bu.domain.asn1.VamContent
+import com.hawhamburg.micr0bu.domain.asn1.VamUperCodec
 import com.hawhamburg.micr0bu.domain.cam.CamTransmitConfig
 import com.hawhamburg.micr0bu.domain.cam.PhoneCamBuilder
 import com.hawhamburg.micr0bu.domain.usecase.GeoMath
+import com.hawhamburg.micr0bu.domain.vam.VamGenerationRules
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -45,12 +50,19 @@ import javax.inject.Singleton
 * [com.hawhamburg.micr0bu.domain.detection.EventDetector] stream that already drives trip event
 * logging). Both rate figures are placeholders pending real-world tuning, per
 * [CamTransmitConfig]'s own disclaimer.
+ *
+ * ## CAM or VAM
+ * Settings chooses what goes out ([OutgoingMessage]). CAM follows the rate policy above. VAM is
+ * checked every [VAM_TICK_MS] against the generation rules of TS 103 300-3 clause 6.4
+ * ([VamGenerationRules]) and sent when one fires, from the same GNSS fix, pseudonym and position
+ * vector a CAM would use. Whether either is signed is the "Sign outgoing messages" setting; the
+ * micrOBU does the signing ([Esp32Link]).
 */
@Singleton
 class CamTransmitLoop @Inject constructor(
    @ApplicationContext private val context: Context,
    private val obuHardwarePrefs: ObuHardwarePreferences,
-    private val usbSerialTransport: UsbSerialTransport,
+    private val esp32Link: Esp32Link,
    private val codec: RealAsn1UperCodec,
    private val pseudonymManager: PseudonymManager,
 ) {
@@ -67,6 +79,10 @@ class CamTransmitLoop @Inject constructor(
    /** Previous GNSS fix, kept only to derive along-track acceleration — see [longitudinalAccel]. */
    @Volatile private var previousGnss: GnssReading? = null

+    @Volatile private var outgoing: OutgoingMessage = OutgoingMessage.CAM
+    @Volatile private var signOutgoing: Boolean = true
+    private val vamRules = VamGenerationRules()
+
    /**
     * Call when a braking/turning/stopping event fires during an active trip — bumps the CAM
     * rate to [CamTransmitConfig.elevatedRateHz] for [ELEVATED_HOLD_MS] so nearby stations get
@@ -85,6 +101,7 @@ class CamTransmitLoop @Inject constructor(
        if (job?.isActive == true) return
        elevatedUntilMs = 0L
        previousGnss = null
+        vamRules.reset()
        job = scope.launch {
            obuHardwarePrefs.obuHardwareFlow.collectLatest { hardware ->
                if (hardware != ObuHardware.ESP32_C5) return@collectLatest
@@ -102,24 +119,66 @@ class CamTransmitLoop @Inject constructor(
    private suspend fun runTransmitLoop() = coroutineScope {
        launch { sensorRepository.gnssFlow().collect { latestGnss = it } }
        launch { sensorRepository.gyroscopeFlow().collect { latestGyroZ = it.z } }
+        launch { obuHardwarePrefs.signOutgoingFlow.collect { signOutgoing = it } }
+        launch {
+            obuHardwarePrefs.outgoingMessageFlow.collect {
+                if (it != outgoing) vamRules.reset()
+                outgoing = it
+            }
+        }

        while (true) {
            val gnss = latestGnss
            if (gnss != null) {
-                // Asked for per CAM rather than once per trip: that is what lets a pseudonym
-                // rotation fall cleanly between two frames instead of inside one.
-                val pseudonym = pseudonymManager.current()
-                // Stamped on GNSS time rather than the phone clock; see GnssTimeSource. Only the
-                // outgoing CAM is: acceleration below still differences wall-clock samples.
-                val fix = gnss.copy(timestamp = GnssTimeSource.correct(gnss.timestamp))
-                val cam = PhoneCamBuilder.build(fix, latestGyroZ, pseudonym.stationId, longitudinalAccel(gnss))
-                val bytes = codec.encodeCam(cam)
-                usbSerialTransport.sendCamTx(bytes, GnPositionVector.fromCam(cam, gnss.accuracyM, pseudonym.mac))
+                when (outgoing) {
+                    OutgoingMessage.CAM -> sendCam(gnss)
+                    OutgoingMessage.VAM -> sendVamIfDue(gnss)
+                }
            }
-            delay((1000.0 / currentRateHz(gnss)).toLong())
+            delay(if (outgoing == OutgoingMessage.VAM) VAM_TICK_MS else (1000.0 / currentRateHz(gnss)).toLong())
        }
    }

+    private suspend fun sendCam(gnss: GnssReading) {
+        // Asked for per CAM rather than once per trip: that is what lets a pseudonym
+        // rotation fall cleanly between two frames instead of inside one.
+        val pseudonym = pseudonymManager.current()
+        // Stamped on GNSS time rather than the phone clock; see GnssTimeSource. Only the
+        // outgoing CAM is: acceleration below still differences wall-clock samples.
+        val fix = gnss.copy(timestamp = GnssTimeSource.correct(gnss.timestamp))
+        val cam = PhoneCamBuilder.build(fix, latestGyroZ, pseudonym.stationId, longitudinalAccel(gnss))
+        val bytes = codec.encodeCam(cam)
+        esp32Link.send(OutgoingIts(OutgoingMessage.CAM, bytes,
+            GnPositionVector.fromCam(cam, gnss.accuracyM, pseudonym.mac), gnss.accuracyM, signOutgoing))
+    }
+
+    private suspend fun sendVamIfDue(gnss: GnssReading) {
+        val now = System.currentTimeMillis()
+        val kinematics = VamGenerationRules.Kinematics(gnss.latitude, gnss.longitude,
+            gnss.speedMs.toDouble(), gnss.bearingDeg.toDouble())
+        if (!vamRules.due(now, kinematics)) return
+        val pseudonym = pseudonymManager.current()
+        val fix = gnss.copy(timestamp = GnssTimeSource.correct(gnss.timestamp))
+        // The CAM view of this fix is built only for its position vector, so the GN header of a VAM
+        // follows exactly the rules a CAM's does. It is not transmitted.
+        val cam = PhoneCamBuilder.build(fix, latestGyroZ, pseudonym.stationId, longitudinalAccel(gnss))
+        val withLowFrequency = vamRules.includeLowFrequency(now)
+        val bytes = VamUperCodec.encode(VamContent(
+            stationId = pseudonym.stationId,
+            timestamp = cam.timestamp,
+            latitude = cam.latitude,
+            longitude = cam.longitude,
+            accuracyM = gnss.accuracyM,
+            speedMps = cam.speedMps,
+            headingDeg = cam.headingDeg,
+            accelerationMps2 = cam.accelerationMps2,
+            includeLowFrequency = withLowFrequency,
+        ))
+        val handedOver = esp32Link.send(OutgoingIts(OutgoingMessage.VAM, bytes,
+            GnPositionVector.fromCam(cam, gnss.accuracyM, pseudonym.mac), gnss.accuracyM, signOutgoing))
+        if (handedOver) vamRules.onSent(now, kinematics, withLowFrequency)
+    }
+
    /**
     * Along-track acceleration in m/s², from the change in GNSS speed since the previous fix.
     *
@@ -158,6 +217,9 @@ class CamTransmitLoop @Inject constructor(
    companion object {
        private const val ELEVATED_HOLD_MS = 5_000L

+        /** How often VAM generation rules are checked: T_GenVamMin, TS 103 300-3 Table 16. */
+        private const val VAM_TICK_MS = VamGenerationRules.T_GEN_VAM_MIN_MS
+
        /** Below this gap, GNSS speed noise divided by a tiny dt produces absurd accelerations. */
        private const val MIN_ACCEL_DT_SEC = 0.2