单片机测速_毕业设计.doc

摘要随着科技的发展，单片机的应用，带动传统控制检测更新。接触车速传感器代替软轴传动,可使车速表安装位置不受距离限制有效地克服了机械式车速表中的诸多不足给出了以AT89C2051为核心，利用单片机运算和控制功能，并采用系统化LED显示模块实时显示所测速度的设计方案以及串口数据存储电路和系统软件。该方案由于使用了显示模块和E2PROM，以及高效快速算法，因而可在节约系统资源和简化程序设计的基础上保证测量精度和系统实时性。,以降低对待测信号的幅度要求；波形变换和波形整形电路则用来将放大的信号转换成可与单片机接口的TTL 信号。通过单片机的设置可使INT0 引脚能够对内部定时器T0 的工作进行控制,这样能精确地测出加到INT0 引脚的正脉冲宽度(即测出脉冲信号的期) 。速度显示部分采用数码显示, 所得的数据采用I2C总线, 并通过E2PROM来存储, 因而节省了所需单片机的口线和外围器件, 同时也简化了显示部分的软件编程。 本方案实现了电动车速度即时显示，并可通过控制两个按键显示速度或里程，同时加入了超速语音报警功能，使之更加人性化。 关键词：单片机显示Abstract With the rapid development of technology, more and more widespread application of microcomputer, and promote the traditional control detection technology constantly updated. Most of the current electronic speedometer, and with the LED digital tube or LCD display real-time, display more intuitive. Electronic speedometer flexible shaft using the contact speed sensor instead of driving, speed tables can be installed without distance limitations, and further to effectively overcome the mechanical disadvantages of speed in the table. The AT89C2051 is designed to give the core of computing and the use of microcomputer control, and adopting a systematic LED display module shows the measured real-time speed design, and the serial data storage circuits and system software. The program due to the use of the digital display module and E2PROM, and efficient fast algorithm, thus saving resources and simplifying programming system based on the system to ensure accuracy and real-time. Signal pre-processing circuit which includes signal amplification, wave conversion and waveform shaping: signal pre-processing circuit in the amplifier for the amplified signal could be to reduce the requirements on signal amplitude; wave transformation and wave-shaping circuitry is used to enlarge the signal converted into TTL signals with the microcontroller interface. Set by MCU enables INT0 pin to the work of the internal timer T0 control, so to accurately measure the INT0 pin is added to the pulse width (ie measu