模拟乒乓球游戏机，输入有按键消抖模块，利用两个七段数码管的其中9段来模拟乒乓球的移动路线，中间的数码管兼做球网。-Table tennis simulation game, enter a key debounce module, using two seven-segment digital tube to simulate the Table Tennis section 9 of the mobile line, cater to the middle of the digital net