The Design And Implementation Of Vehicle Carried Embedded Terminal Based On GPS/GPRS

The vehicle carried terminal described in this paper is used in vehicle supervising system, Relying on GSM/GPRS network run by China Mobile, the terminal can upload GPS data to monitor center and receive the dispatched orders from the center. The interval of data sampling and the halt of the terminal can also controlled by the center. The terminal (Preliminary version) has been realized successfully by PHILIPS LPC2138 microcontrollers (based on a 32/16 bit ARM7TDMI-S CPU) embedded with Real Time Operating SystemμC/OS-II (V2.52), WAVECOM Q2406B GSM/GPRS module and HOLUX GM82 GPS module. Its characteristics are as follows:The terminal's software system is different from conventional foreground/ background system, and it is constituted by 9 tasks embedded inμC/OS-II. As a result, the real time character and expansibility of the terminal are improved.Based on the hardware interface of SD/MMC, included in preliminary terminal and File system, the next version terminal can record the travel track data.The event flag and mutual exclusion semaphores ofμC/OS-II, which are seldom adopted in other software system based onμC/OS-II, are used to control the communications between these tasks and to administer sharable hardware resources.Adjusting the software, the terminal can be changed into theft-against system or self-navigation vehicle carried device.The selection of the project is based on lots of on-the-spot investigations, and it emphasizes particularly on the implementation of the design theory. Therefore, this paper expounds the project in detail including software development, PCB design and debugging of the whole system. In other words, this paper opens out many technical methods that are being used in many commercial projects.