主要目的就是要从传感器中收到两个正弦信号，用单片机进行计数。并传送到上位机来进行显示。

SPEED为采集到正弦信号并用T0，T1来计数。知道16位计数器能够一次计完。

用T2来设定波特率。并发送计数器计的脉冲个数。假如上位机的接受信号为58。-　The main aim is received from the sensors two sinusoidal signals with a microcontroller to count. And send to the host computer to be displayed.　 SPEED is collected and used sinusoidal signals T0, T1 to count. Know the 16-bit counter can be a total end.　 With T2 to set the baud rate. And sends a pulse counter account number. If the host computer' s receive signal 58.