用AT89C51接ADC0809并编一个程序：分别给ADC0809的两个输入口分别输入0~5V的电压，在C51的四个输出口对应输出高低电平。-ADC0809 with AT89C51 and then compile a program: ADC0809, respectively, to the two input ports, respectively, 0 ~ 5V input voltage, and in four C51 output port corresponding to the output high and low.