汽车在线诊断(OBDII)通用接口转换器FPGA的设计与实现

Design and Implementation of the General Interface Converter with FPGA Based on the On-board Diagnostics

针对常用的OBDII信号标准SAE J1850的两种编码方式PWM和VPW,设计出PWM接口与计算机通用接口RS 232之间的格式转换器,并用FPGA实现。该通用接口转换器为OBDII系统与计算机之间的通信提供接口,使普通计算机可以监视到汽车的故障状态和参数,配合适当软件即可构成一个功能强大而且价格低廉的汽车故障诊断仪。

In this paper, we set the two code schemes of SAE J 1850, which are OBDU signal standard in common use, as the research object to design a format converter between the signal of PWM and that of RS 232. It provides a communication interface between the OBDII system and the computer,so that the computer can monitor the state and the parameter of the ear. It could work as an OBDII scan tool of powerful function and low cost, if proper software is taken too.