A DBC file describes a car’s network traffic, what modules are on it, and their messages and signals.

Example

BO_ 342 STEERING_SENSORS: 6 EPS

BO_342 A group of messages and their id (ID is in decimal numbering). 342 is equivalent to 0x0156 hexadecimal format.

SG_ STEER_ANGLE : 7|16@0- (-0.1,0) [-500|500] “deg” EON

  • SG_ STEER_ANGLE A description of a signal.
  • 7|16: This signal starts at bit position 7, and the size is 16 bits. 16 bits is common for a steering angle. Here is what this looks like in cabana’s bit view:
16 bit value, starting at position 7 — 7|16
Big Endian
Little Endian
Example of big endian bit position numbering, the highlighted value would be 3|4@0+
  • “deg”: Units, in this case, it is degrees.

Hex

0x156–00 06 00 00 07 2d

Binary

0000000 00000110 00000000 00000000 00000111 00101101

Displayed in cabana

Cabana makes it easy to visualize a DBC file
Viewing car’s steering angle with DBC + Cabana
Viewing steering angle and blinker with Cabana

engineer, hacker, early-adopter https://github.com/energee https://energ.ee

engineer, hacker, early-adopter https://github.com/energee https://energ.ee