Briefing
Finding one signal's CAN ID, start bit, length, byte order, scale and offset by hand can take hours. The skill surveys bus activity to flag counters and checksums, ranks candidate IDs and bytes by correlation, and runs a bit search for the exact field. It then fits the scaling and writes a DBC file with verification plots, which loads into CSS's webCAN software.
The three demos decode speed and RPM on a Mercedes E350 from OBD2, Opel Astra speed from dashboard video, and gauge positions on a CANmod.input bench. CSS says each signal takes 5 to 10 minutes with a clean reference. The CANsub.2 can record in listen-only mode, but an OBD2 reference means sending requests to the vehicle. Free sample data covers the workflow without a car.
Written by the Boards & Bots curator