基于單片機(jī)的汽車防盜報警系統(tǒng)設(shè)計 中英文參考資料-文庫吧
2025-05-16 12:00 本頁面
【正文】 icity coupler outputs the TP1 end is 1, the permission ultrasonic wave launch, launches/the receive ultrasonic wave in turn, the circulation repeatedly carries on. Simultaneously the monolithic integrated circuit interior counter starts to count. The steam distance between vehicles obstacle distance is the time which sends out through the sound navigation and ranging reflects spends determines and carries on the putation. The reflection signal causes the D trigger to produce interrupt request signal INT1,simultaneously stops counting, reads takes counts the value, calculates the actual distance after the formula, then carries on the parison with the datum distance, if examines when the actual distance is bigger than reference value 80cm, does not carry on the accustomoptics to report to the police。 If some people approach the automobile to enter the cab, the examination actual distance is smaller than or was equal to when reference value 80cm, through monolithic integrated circuit and the port, actuates the indicating lamp display circuit and the sound alarm circuit, sends out three two flash. And triggers a high level, the actuation is wire less signal transmission circuit.Chart 1 Ultrasonic wave transmission circuit Code/decoding principleThe present automobile remote control security system are many is usesVD5026/27, PT2262/72, HT12E/D and so on the general code/decodes the electric circuit, its password decided by the ponent address, each set of security systems use a fixed invariable password. Along with the micro processing technology development, through the receiver emote control transmitting message, may intercept this fixed password, moreover general arranges the decoding address to lose the person to carry the ponent size limit, its quantity is impossible too much, can obtain not repeatedly codes very is also limited, also can very quickly explain the password with the automatic scanner. Therefore, this kind of password fixed invariable automobile security system has received the serious threat. Decodes the automobile security system using the monolithic integrated circuit interior resources realization jump code, it each time uses the remote control password all is changing, with the password no longer duplicates uses, causes the interception password also is makes a futile effort, in addition, it may increase the enough many passwords figure, enhances the system resistance illegal scanning the ability. The remote control coding altogether has 12 bytes, separately by 3 bytes codes channels code, 3 bytes codes forewords number, 5 bytes jumps codes, 1 byte pressed key operation code is posed. Encoded front adds on logic in each byte 0 to take the outset position, encoded behind adds on a logical 1 achievement in each byte to stop the position, and in most front adds on several logic 1 to take the guidance signal, this constituted the seria
公司管理相關(guān)推薦
鄂ICP備17016276號-1