程控变速小车的设计(论文).doc

摘 要 本文介绍了单片机控制步进电机的系统。89C51单片机是一款8位单片机，它的易用性和多功能性受到了广大使用者的好评。在电气时代的今天，电动机一直在现代化的生产和生活中起着十分重要的作用。步进电机是机电控制中一种常用的执行机构其原理是通过切换每相线圈中的电流和顺序来使电机作步进式旋转。本系统的硬件组成以51系列单片机为控制核心，主要部件还有ULN2003A驱动电路、74HC573、数码管、直流电压源、无线串口模块等。本系统用51系列单片机和ULN2003A电机驱动芯片并加入了按键和无线串口两种方式来控制步进电机实现换向、变速、停止等，并以74HC573控制数码管显示档位。系统中使用的是永磁式四相六线步进电机，相应的驱动和控制电路对于其整体性能起着非常重要的作用。 经系统调试，能够很好的控制步进电机的正反转、加减速、急停、显示档位、远距离控制，从而达到预期目的。整个系统具有结构简单、可靠性高、成本低和实用性强等特点，具有较高的通用性和应用推广价值。 关键词：MCS-C51单片机 ULN2003A步进马达 串口通信 In this paper, we introduce a stepper motor system controlled by MCU 89C51 which is a 8 bit single chip computer. Its easily using and multi-function suffer large users. In the Electrical era, motor has been playing a very important role in the modernization of production and daily life. Stepper motor is a common used implementing agency in motor control. The principle is switching the coil current and the order in its each phase to make a step-by-step rotary motor. The hardware of the system adopting 89C51 for controlling core ,includes ULN2003A driving circuit, M74HC573, digital tube displaying , DC voltage source , wireless serial port module etc. At the same time, some of the software used in system designing are introduced. The system uses 51 MCU and ULN2003A motor drive chip and the keyboard to control the stepper motor to achieve the direction and speed of rotation, etc. A permanent magnet two-phase stepper motor is used in the system. The corresponding drive and control circuit plays a very important role to its overall performance. Through system test, it can be very convenient to control the stepper motor, such as acceleration , deceleration, exigency stop，telecontrolling so as to achieve the desired objectives. The whole system is simple in structure with characteristics of high reliability, low cost and practicality which has a higher universal characteristic and the promotional and applied value. Keywords: MCS-C51 ULN2003A stepper motor Serial communication目 录 1 1.1