his class covers the basics of the SAE J1939 vehicle communications bus standard, including source code and other examples from the author’s experience implementing this protocol in several popular microcontrollers and operating systems. Topics covered include: CAN 2.0b; PDU1/PDU2 Message Formats; Parameter Group Numbers (PGN); address arbitration; connection management. Lessons learned, techniques for performance enhancement, and failure detection and recovery are also discussed.