Usb Communication Interface In A Vehicle Traveling Data Recorder

Vehicle traveling data recorder is used to record the status, such as velocity, time and mileage, of the vehicle and store the information that should be exported to the computer or other devices through the communication interface. In the study, the main work of mine is to design and realize the communication interface of the recoder, and my emphase is how to design the USB interface, we introduce the scheme of tranfering data. The main content of this paper includes:First, I introduce the whole of the vehicle traveling data recorder, and then discuss the communication interface of the recoder in detail.The communication interface of the recoder include: USB interface and RS232 interface. This paper will introduce them from two part :In the part of the hardware, firstly brief introduce USB bus and RS232 bus, then describe the circuit diagram of the recorder, and write up the information of the main chips(serial interface chip MAX232 singlechip W78E54 USB interface chip SL811HS), and write up some information about how to use them. In the part of the software, firstly introduce debugging tools, then analyze the RS232 data communication protocol and the USB 1.1 protocol; on these elements, write up the function of every software module, and draw the flow chart of the program; in addition, introduce mass storage protocol FAT file system, because in the program it needs some knowadge about them. We synthetize the hardware and software, and realize the function of the communication of RS232 serial interface the function of the recorder reading and writing USB disk.At last, i bring forward one example of the applications.and sum up the project.