关于芯片ADC0804的模数转换实验。首先启动芯片ADC0804开始模数转换，接着单片机在接收到串口调试工具发送的一个数字之后，单片机将转换后的数字信号的值读出来，并返回发送给串口调试工具，并在其窗口中显示出来。-IC ADC0804 test for AD signal convert. Start the IC AD and make it work. After 51MCU received one number from the serial communication tool, then 51MCU send the AD converting result to the serial communication tool and display the result on the screen.