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.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Enumeration:
- Merge the library's stock probe table instead of replacing it, so adding
Espressif 0x303A/0x1001 doesn't drop every other supported device
- Select the ESP32-C5 by VID/PID rather than list position
- Log USB interface descriptors to distinguish CDC data from the JTAG interface
Lifecycle:
- Don't close the shared port in MqttViewModel.onCleared() - the foreground
recording service outlives the ViewModel and would beacon into a dead port
- Handle ACTION_USB_DEVICE_DETACHED so the UI stops reporting a stale link
- Implement the STATUS heartbeat on both sides (1 Hz) plus a phone-side watchdog
- Surface write failures and firmware drop counters on the CAM Pinger card
Protocol:
- Assert DTR/RTS on open (unverified on hardware - see FLASHING.md step 5)
- Raise SERIAL_LINK_MAX_PAYLOAD 160 -> 512 on both sides; real third-party CAMs
exceed 160 and were being silently dropped at the resync branch
- Move the enlarged buffers off task stacks; serialize send_frame with a mutex
Firmware and app must be updated together - a 512/160 mismatch fails silently.
- Firmware: rewrite obu-firmware TX loop to be serial-driven (no on-chip timer), add promiscuous RX + GeoNetworking/BTP unwrap (gn_unwrap.c), add binary UART framing to the phone (serial_link.c/.h). Drop local cam_encode() - CAM is now built on the phone.
- Kotlin: byte-exact UPER CAM encoder/decoder ported from cam.c (BitWriter/BitReader/CamUperCodec), matching SerialFrame codec, real UsbSerialTransport (usb-serial-for-android), CamTransmitLoop (1Hz base rate, event/geofence boost, ESP32-C5-only), wired into CamUseCaseRepository for RX and TripRecordingService for TX.
- Add V2X message retention: persist all CAM (own+remote) to Room while recording, drop otherwise (DB v2 -> v3 migration).
- Add jitpack repo + usb-serial-for-android dependency.
Fixes: UsbSerialTransport now uses SerialInputOutputManager.start()/stop() (this lib version manages its own thread internally) instead of manual Runnable/Thread submission, which didn't compile.
