基于单片机可变增益放大器

#include<reg51.h> #define uchar unsigned char #define uint unsigned int uchar table[]={0x3f,0x06,0x5b,0x4f}; //共阴0-3 uchar k1,value; main() { //P0=0X00; while(1) { P0=0X0FF; k1=P0; switch(k1) { case 0x0ff: value=0;break; case 0x0fb: value=1;break; case 0x0f9: value=2;break; case 0x0f8: value=3;break; } P2=table[value]; P3=0X0FC|value; } }