说明：  实物调试，labview通过usb转ttl电平控制AVR单片机，实现串口测试：发送hello字符返回ok！读取单片机I/0口，更改数码管显示等功能。
(Physical debugging, labview through usb to TTL level control AVR microcontroller, realize serial testing: send hello character return ok! Read the microcontroller I/0 interface, change the digital tube display, and other functions.)