Home
    ├ Intro                     — two sentences, no slogan
    ├ Map example               — screenshot + legend, link to the live map
    ├ At a glance               — 5.9 GHz (ITS-G5/802.11p) · ESP32-C5, ~20 EUR
    │                             · unencrypted but signable · MQTT · CC BY-SA 4.0
    ├ Data flow                 — receive → publish via MQTT → the map
    ├ Running a receiver        — official node OR your own project → Receivers
    ├ Documentation             — link list to all pages
    └ Project                   — source (Codeberg) · talk (media.ccc.de/GLT26)
                                  · non-profit · imprint

What is C-ITS?                  — conceptual only
    ├ How it works              — 5.9 GHz, unencrypted but signable; vehicles <-> infrastructure
    └ Message types             — CAM · DENM · MAPEM · SPATEM · IVIM

Senders                         — who transmits C-ITS
    ├ Sender types              — RSUs (traffic lights, roadworks signs, toll gantries)
    │                             · OBUs (trams, buses, cars, emergency vehicles)
    ├ Vehicles: Volkswagen group— Golf 8, ID.3/4/5/7, ID.Buzz, Multivan, Tiguan III,
    │                             Passat B9, Tayron, T-Roc II; >2.3M; changing pseudonyms
    ├ Vehicles: Cupra           — Born (Tech Pack), Tavascan, Terramar
    ├ Not receivable            — cloud "Car-to-X": Mercedes/BMW/Ford/Volvo/Audi/Skoda
    ├ Infrastructure            — ASFINAG, Autobahn GmbH, Car2X traffic lights, transit OBUs
    ├ Outside Europe            — USA DSRC (dead) · Japan ITS Connect 760 MHz
    │                             · China C-V2X (both incompatible)
    └ In practice               — what you actually receive around here

Coverage                        — where C-ITS is live (purely geographic)
    ├ How this list works       — deployment vs. community sighting; how to add one
    ├ Legend                    — signed yes/no, OBU-only, ...
    ├ Austria                   — Graz · Klagenfurt (12 RSU / 74 bus OBU) · Vienna · ASFINAG
    └ Germany                   — Autobahn · Aachen · Braunschweig · Hamburg (bus priority)
                                  · Kassel · Munich

Receivers
    ├ The official receiver
    │     ├ Get one             — group order (Pretix, 20 EUR, pickup at realraum Graz,
    │     │                       shipping AT/DE/own label) · or have the PCB made
    │     ├ Board reference     — ESP32-C5-WROOM, revisions, jumpers, u.FL, schematics
    │     ├ What's in the box   — ASA enclosure, bottom seal (bottom.stl) + M4x12 TX20,
    │     │                       rubber plug for the LAN cable
    │     ├ Power               — USB (~1.7-2 W) vs. PoE; jumper table (802.3af /
    │     │                       passive 7-58 V); never USB and PoE at the same time
    │     ├ Getting online      — LAN/DHCP · no WiFi · mobile: repeater with LAN port
    │     ├ Config              — no local web UI; via the portal (MQTT) or via USB
    │     ├ LEDs & troubleshooting — LED table (SYS/RCV/ETH/MQT/PKT), brightness
    │     ├ Compliance & EMC    — EMC test rev 2 (FH Villach), class B passed; CE path
    │     └ Next steps          — -> Placement · -> Your Node · -> Reporting to OTM
    │
    └ Other receiver projects   — catalogue; fields: hardware · firmware · uplink · to OTM? · repo
          ├ DIY Ethernet        — ESP32-C5 + W5500/ENC28J60, OTM firmware, wired
          ├ WiFi via SPI-EPPP   — ESP32-C5-DevKitC-1 (N4R2) + companion ESP32-C3
          ├ USB -> Raspberry Pi — ESP32-C5 + Pi as gateway
          ├ USB -> Android      — ESP32-C5 + phone as gateway (cits-to-go)
          ├ Mobile 5G setup     — FireBeetle 2 ESP32-C5 + W5500 + power bank + ZTE MU5001
          ├ ESPHome firmware    — official OR any C5 hardware; esphome-its-g5
          ├ FritzBox 3390       — AVM 3390 (AR9580/ath9k), OpenWrt + otm-bridge
          └ v2x2map             — Waveshare C5-WIFI6-KIT, fork with its own app and map;
                                  standalone, OTM upload optional

Placement & Outdoor
    ├ Mounting & line of sight  — higher is better; outdoor beats indoor; tinted windows reflect
    ├ Interference              — nearby 5 GHz WiFi -> separate or disable the 5 GHz band
    ├ Antennas & polarization   — internal PCB antenna is good; external (u.FL): vertical better
    ├ Temperature               — typ. ~55 C, up to 83 C in the sun; dim the LEDs; use shade
    ├ Enclosure                 — ASA (UV-resistant, waterproof), bottom seal + LAN grommet
    └ Surge protection          — one arrester per outdoor run, inline before the switch, grounded

Your Node                       — Self-Service Portal; applies to EVERY node
    ├ Accessing your node       — QR code on the case / link from the shipping mail
    ├ Password protection       — set a user password, otherwise the portal is open
    ├ Friendly name             — a readable name instead of the raw MAC
    ├ Show on map & coordinates — map visibility, setting the location
    ├ Node settings             — LED brightness (0-255), reboot
    ├ View your messages        — your own frames in the portal
    └ Heatmap                   — reception heatmap of your node

Reporting to OTM                — the MQTT broker; convergence point of ALL receivers
    ├ The central broker        — every node publishes to one broker -> the map; publish without login
    ├ Wire format               — raw 802.11p/C-ITS frames; one format for all projects
    ├ Connecting                — host/port from the firmware config.c; node name = MAC by default
    ├ Topics                    — its/nodeXXX/packet/json · .../stats · wildcard its/nodeXXX/#
    ├ Subscribe to your node    — credentials from the portal; MQTT client list
    ├ What is published         — CAM/DENM/MAPEM/SPATEM/IVIM + telemetry; no offline buffer
    └ Monitoring in Home Assistant — node publishes telemetry, HA reads along via MQTT
                                  (HA *as a receiver* -> ESPHome in the catalogue)

Using the data                  — API (currently a stub)
    └ Overview · Endpoints · Data formats (GeoJSON/JSON) · Access & limits

Community
    ├ Contributing              — edit rights, style guide
    ├ Language policy           — English
    ├ Non-profit & finances     — OpenTrafficMap association, volunteer-run, donations
    ├ Related projects          — Codeberg org, firmware repos, cits-to-go, EPPP server,
    │                             v2x2map, esphome-its-g5, FritzBox bridge
    ├ Further reading           — external C-ITS resources
    └ Imprint & license         — CC BY-SA 4.0, imprint