在VB环境下利用Mscomm控件，向单片机发送数据（每按一下发送按钮即向单片机发送1个字节）， 使单片机接收到该数据后，马上再将该数据发送到VB当中。-In the VB environment using Mscomm control, sending data to the MCU (each click on the Send button to send a byte immediately SCM), SCM received the data so that immediatel