本文介绍基于单片机AT89C51控制的自动往返电动小汽车控制系统的硬件和软件设计。 关键词:AT89C51芯片;自动往返电动小汽车;光电检测器 Abstract: This paper introduces a kind of hardware and software design, which is the system of automatically back and forth electric car controlled by MCU AT89C51 . Keywords: the clip of AT89C51; automatically back and forth car; photoconductor measuring tube