1、 设计一个由甲、乙双方参赛，有裁判的3人乒乓球游戏机。

2、 用8个(或更多个)LED排成一条直线，以中点为界，两边各代表参赛双方的位置，其中一只点亮的LED 指示球的当前位置，点亮的LED依此从左到右，或从右到左，其移动的速度应能调节。

3、 当“球”(点亮的那只LED)运动到某方的最后一位时，参赛者应能果断地按下位于自己一方的按钮开关， 即表示启动球拍击球。若击中，则球向相反方向移动；若未击中，则对方得1分。

4、 一方得分时，电路自动响铃3秒，这期间发球无效，等铃声停止后方能继续比赛。

5、 设置自动记分电路，甲、乙双方各用2位数码管进行记分显示，每计满21分为1局。

6、 甲、乙双方各设一个发光二极管，表示拥有发球权，每隔5次自动交换发球权，拥有发球权的一方发球 才有效。

-1, the design of a competition by the A and B sides, there are three tennis referee consoles.

2, with eight (or more) LED arranged in a straight line to the midpoint for the community, participating representatives of both sides of each position in which a lit LED indicates the current position of the ball, so the lit LED left to right, or right to left, which should be able to adjust the speed of movement.

3, when the　ball　(bird lit LED) moves to the last bit of a party, the participants should be able to decisively press button switch located on their side, that means start hitting the racket. If you hit the ball moving in the opposite direction　if not hit, you get 1 point each other.

4, when the party scored, the circuit automatically ring 3 seconds, during which serve invalid, and so can only continue the game after the ringing stopped.

5, set up automatic scoring circuit, A and B sides each with two digital tube display the score, at least 21 per meter into an office.

6, A