联想校园招聘笔试题

根据这个程序选出最可能实现的功能是什么？ #include <Arduino.h> #include <analogWrite.h> void setup(){ } void loop(){ for (int i = 0; i <= 255; i = i + (1)) { analogWrite(2, i); delay(10); } for (int i = 255; i >= 0; i = i + (-1)) { analogWrite(2, i); delay(10); } }