The hardware design is based on our SAE J1939 Gateway Module With USB Port, RTC, MicroSD Memory Card. This gateway board is a high-performance, low-latency vehicle network adapter for SAE J1939 applications. It allows any host device with a USB COM port to monitor SAE J1939 data traffic and communicate with the SAE J1939 vehicle network.
The board supports the full SAE J1939 protocol according to J1939/81 Network Management (Address Claiming) and J1939/21 Transport Protocol (TP). It is also supported by an extensive programming interface for Windows and Linux/Ubuntu applications, including full C/C++/C# source code for short time-to-market developments.
The strength of the board lies in the fact that the entire SAE J1939 protocol, including all timing requirements, is stored on-chip, thus taking the burden off the main system.
The board supports a USB transfer rate of up to 480 Mbps, allowing high data throughput. Also, the onboard real-time clock supports the timestamping of the SAE J1939 data frames (PGN). Furthermore, the board comes with a MicroSD memory card slot, which opened the door to future applications such as a SAE J1939 data logger.
We have created a prototype (as shown to the right) based on the above-mentioned USB board, extended by a power-supply board that accepts a power input range of 7 VDC to 36 VDC as it applies to diesel engine operation.
The terminals for power and CAN Bus connection will be replaced by a 9-pin DSUB connector, while the USB connection will be changed from USB-mini to a USB 2.0 design to assure operation under harsh environmental conditions (dust, splash-water).
- The board size will be increased to fit the additional power supply components.
- The only external components will be the USB port and the CAN/Power Supply DSUB-9 connector.
- The USB connection will be USB 2.0 to meet the challenges of harsh environments.
- The SD card will be accessible through opening the enclosure.
- The 120 Ohm termination resistor is activated per onboard jumper.
- The board will have no LEDs to lower power-consumption (reducing battery drain).