Commit Graph
2 Commits
Author SHA1 Message Date
Ashin Walpola 21e01499d8 Drive the bench CAM beacon round a street loop in St. Georg
The bench transmitter sent a parked car: one fixed position, speed 0,
no heading, a CAM every second. It now simulates a car driving a loop
through six waypoints around Berliner Tor on the real streets, which
makes it a moving target for the app's map and the use case detection
without taking a car out.

The route is generated, not hand-traced. tools/make_route.py asks the
OSRM demo server for a driving route through the waypoints and back to
the first, thins the 371 street points to 103 (none more than 1.5 m off
the line), and writes main/route_points.h. It also saves OSRM's answer
(--offline rebuilds from it) and a map page to check the route before
flashing. Each waypoint is sent with the direction towards the next one:
without it, points on divided roads such as Beim Strohhause snapped to
the opposite carriageway and the loop came out at 8.4 km of U-turns.
With it the loop is 5.2 km, still including two turn-round detours
that OSRM needs to reach the waypoints legally (Borgfelder Strasse /
Anckelmannsplatz, and Nagelsweg / Norderstrasse / Repsoldstrasse).
Route data (c) OpenStreetMap contributors, ODbL.

main/route.c moves the car along the points. It cruises at 50 km/h and
limits each bend to the speed that keeps sideways acceleration at
2 m/s^2, so a junction turn is taken at about 15 km/h and a gentle curve
barely slows it; braking (2 m/s^2) and acceleration (1.5 m/s^2) are
planned across as many points as a bend needs. A simulated lap on the
host is 5.16 km in 7.7 min, averaging 40 km/h.

CAMs now follow the EN 302 637-2 generation rules instead of a fixed
1 Hz: checked every 100 ms, sent on a heading change over 4 degrees, a
move over 4 m, a speed change over 0.5 m/s, or after 1 s - about 3 Hz
at 50 km/h. generationDeltaTime is milliseconds since boot. The
GeoNetworking source position vector now carries the same speed and
heading as the CAM instead of zeros.

NOTES.md gains build and flash steps (including reading a board's app
descriptor first, since both firmwares name their image
obu_firmware.bin) and a section on the simulated drive. The pointer to
docs/04-transmit-setup.md is corrected: that file is not in the repo.

Flashed to the COM8 board and checked on its console: it starts driving
on power-up and sends CAMs with changing position, speed and heading.
Not yet received over the air.
2026-09-16 14:21:44 +02:00
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.
2026-08-11 14:50:35 +02:00