用定时器1 来改变小灯的状态，T1 每溢出两次，两个小灯闪烁一次，并且在停止闪烁后成闪烁前相反的状态。-Timer 1 to change the status of a small lamp, T1 overflow twice each, two small lights flash once, and stops flashing before flashing to the opposite state.