1.此程序非常简洁它不是进行键扫描,而是直接读Pn口,修改很方便,

不受键位置的影响,比如:要改变键号位置只需改变keytable表顺序既可,

且很容易改成双键或多键同时按下键值.



2.还有一种放法是先读行值,再读列值然后行值*4+列值,此种放法也简洁但

可修改性不大好,而且要用乘法运算,代码相对大.



3.可很容易变通应用在多键键盘,比如8*8键盘或更多,代码多不了多少,

只是增大keytable表就可以-1. This program is very simple and it is not the key scan, but a direct reading of Pn mouth, easy to modify, without the impact of key positions, such as: number keys to change the location of the order can only change the keytable table, and it is easy to change into a double bond or more keys are pressed together. 2. there is a release method is to first read the line value, and then read column value row value* 4+ column values, such a release method is also simple but not very good modifiability and use multiplication, the code is relatively large. 3. can easily be adapted in a multi-key keyboard, such as 8* 8 keyboard, or more, not much more code, but can increase the keytable table