51单片机与CPLD的总线通讯程序，简单，实用，内附单片机与CPLD引脚连接原理图。-51 MCU and CPLD bus communication procedures, simple, practical, enclosing the MCU and CPLD pin connections diagram.

51单片机超声波测距程序资料,包括全部的原理图设计，实物图设计，还有完整的程序(51 singlechip ultrasonic ranging program data, including all the schematic design, physical design, and complete program.)