要求程序在电路板上运行时8个LED小灯从最低位开始每隔0.5秒依次亮一个，即开始是最低位小灯亮，其他的灯是灭的，过0.5秒第二个灯是亮的，其他全灭。如此依次往下亮。当到第8个（即最后一个）灯灭后，所有8个灯全亮。然后过0.5秒又是第一个灯亮。如此循环下去。-Application running on circuit board eight LED small light starting　the lowest every 0.5 seconds, in turn, a bright, the beginning is lowest little lights, other lights is quenched, 0.5 seconds the second light is on, other completely destroyed.So in turn down the light.When to the eighth (i.e., the last one) after the lights are out, all eight light full on.Then a 0.5 is the first light.So go down.