This is made by recycling an old CD player that you can get from an old computer, some cardboard, tape, couple of sensors, a few blinking LEDs, and then suddenly you have a tool. You build something that you cannot find on the market.
这个装置使用了一张用过的CD播放器 从一台旧电脑拆下来的 还有一些纸板、胶带、几个传感器和闪烁的LED显示屏 就制作好了这样一个工具 一个市场上买不到的东西