程序实现A/D转换功能，A/D采用中断方式。该程序通过单片机的RA2模拟通道送入一直流电压，当送入的直流电压大于2.5V时，与PORTD口相连的8个发光二极管闪动，当直流电压恢复到2.5V以下时，发光二极管停止闪动，且只有低四个发光。-Program for A/D conversion, A/D with interrupt. RA2 through the program the microcontroller analog channels into a DC voltage into DC voltage when the time is greater than 2.5V, and PORTD port connected to 8 LEDs flashing, when the DC voltage back to 2.5V or less, light-emitting diode stop flashing, and only four light-emitting low.