Blind Way Recognition System Design Base On RFID

China is one of three high-incidence area of blind, about 7 million, accounting for 18% the total number of blind people around the world The average annual number of about 450,000 blind people, almost nearly every minute there will be a new blind, and the total number of Visually impaired people is about 3 times the blind. According to preliminary projections, to 2020, the global number of blind will increase to 75 million people.According to preliminary projections, the global number of blind will increase to 75 million people in 2020.As on the difficult of the bland going out, many countries dedicated a special blind road for the bland .Since 2002, Beijing, Tianjin, Shanghai and the other 12 cities has been establishing to be the construction of barrier-free facilities nationwide model city.Based on this, the Sichuan Provincial Office of Education study of natural science fund projects (082A102) " Blind Way Recognition System Design Base On RFID" is established to Solution this problem. This design is developed with the technology of radio frequency communication and the modern computer communication.Combining the characteristic of the technical development of navigation and the need of the navigation system,the author particularly expatiates on the main idea of designing the hardware system of navigation computer. After analysis and model selection the author designs the overall scheme and hardware circuit. The navigation computer is with a dual CPU structure (DSP and MCU).DSP is used to deal with the audio data while MCU is to control the I/O operation. The DSP and the MCU are designed on the same circuit diagram to realize the navigation system. The function of the CPLD is to carry through the logic coding between the DSP and other equipment. The software design depends on DSP/BIOS. DSP/BIOS is a simple real time OS. Procedure is different from development DSP of tradition,the developer does not need to control DSP completely,operation relevant to the hardware all can draw support from the chip that DSP/BIOS provides supporting a warehouse to be completed. Consumer's application is built above DSP/BIOS basis,preferential step being interrupted under the controller,according to the mission in whose,lines up to wait to carry out.In speech compression, after comparing the waveform coding, the parametric coding and CELP coding,consider voice compression codec algorithm and the rapid and real-time of the DSP, this system have been obtain the best balance between voice resources and the quality of sound.In the GPS module and GSM module, as well as part of the control interface program, this system uses embedded real-time operating system uC / OS-II, completely meet emergency relief needs of the rapid and real-time, in line with market demand for products. In the hardware interface with the DSP , the system uses the HPI interface, facilitate the MCU to collect the GPS data and transmit it to the DSP.The results show that the system in the identification of the RFID and GPS data, voice correctly broadcast to prove the correctness of system design.