Its-g5
| Project ITS-G5 | |
|---|---|
| File:Yunopicture.png | |
| Investigating ITS-G5 signals | |
| Status | In progress |
| Contact | bertrik |
| Last Update | 2026-06-20 |
Introduction
This page is about investigating reception and processing of so-called C-ITS or ITS-G5 signals (802.11p) as used in the Netherlands, see also https://en.wikipedia.org/wiki/Vehicle-to-everything These signals are exchanged between passenger cars, emergency vehicles, traffic lights and other traffic-related equipment.
An ESP32-C5 development board is capable of receiving WiFi in the 5 GHz band and can receive/sniff these kinds of packets from live traffic.
Stuff to investigate:
- Source code for an ITS-G5 receiver https://github.com/pit711/v2x2map
- Crowd-sourced live map of messages received: https://opentrafficmap.org/
- Simplest source code for Arduino-based sniffer: https://git.devlol.org/jstsmthrgk/simple-its-g5-receiver-firmware
In the Netherlands, SPAT/MAPem messages from traffic lights are not transferred over wifi-p, but over UDAP. You need credentials to access that data, it is not clear if it is feasible to hobbyist to access it. Interesting project: https://github.com/idkmanLool9/Verkeerslicht
Hardware
I got this board, and it worked for me:
- aliexpress product page https://nl.aliexpress.com/item/1005012416463528.html
- espressif schematic https://dl.espressif.com/dl/schematics/SCH_ESP32-C5-DevkitC-1_V1.1_20240621.pdf
It has an onboard antenna. There are also other boards with an antenna connection, which allows using an external antenna. This may be better, I don't know yet.
Connect your USB-C cable to the "UART" port.
Software
See https://github.com/bertrik/its-g5-receiver
Compiling
Needs python.
Preparation:
- If you didn't have a python venv, create it:
python -m venv .venv
- Install platformio into the venv:
python pip install platformio
- Finally activate the venv:
bash source .venv/bin/activate
Compile and upload:
pio run -t upload
Watch packets come in:
pio device monitor
Packets are logged as a 'hexdump'.
The can be converted for wireshark, for example:
text2pcap -l 105 message.txt message.pcap
Then viewed in wireshark:
wireshark message.pcap
