N+1键盘的两次原理改进

Two Principle Improvements of N+1 Keyboard

近年来,经常出现计划在原有硬件基础上增加新功能,却发现单片机的I/O资源不够用的情况,虽然改为使用N+1方式的键盘可以节省不少口线资源,但理论上的N+1在实际工作中有一定缺陷,不能适应不同的硬件及结构。笔者根据工作中实际情况两次改进电路,使之能适应不同的硬件和结构。

In the recent years,it is found that the I/O resources are not enough when increasing the new function on the original hard ware. In the paper, the N＋ 1 keyboard system is used to save a lot of port line resources, but the theory of N＋1 has some defects in prac tical work,it can not adapt to all the hardwares and structures. According to the actual situation, the author takes measures twice to im prove the circuit to adapt to the different hardwares and structures.