用74ls164的并行输出端接8个发光二极管，利用它的串入并出的功能，把发光二极管从左到右轮流点亮一个灯，并反复循环。（即流水灯效果）(A parallel output terminal of 74LS164 is used to connect 8 light-emitting diodes. By using its function of string in and out, the LED can turn a lamp on from left to right and circul

74LS143与STM32F103连接，PA.0和PA.1控制A和B的收发，PB.0为时钟控制，连接clock。(The 74LS143 is connected to the STM32F103. PA.0 and PA.1 control the sending and receiving of A and B. PB.0 controls the clock and connects the clock.)