单片机按键有如下效果：

1.按下键立刻获得一个键值,

2.如果按住这个键不动, 等t1时间后获得一个同样的键值,再隔t2时间后获得一个同样的键值

3.不影响主程序

4.使用方便，效率高

-Microcontroller has the following key results: 1. Press the button once to get a key, 2. If you hold down the key does not move, so t1 the same time get a key, and then every time t2 the same key to get a 3 . does not affect the main 4. easy to use, efficient