DA输出控制LED亮度

1、#include<reg52.h>#include<intrins.h>#define uchar unsigned char#define uint unsigned int sbit sda=P20;sbit scl=P21;sbit dula=P26;sbit wela=P27; uchar code table=0x3F,/"0"0x06,/"1"0x5B,/"2"0x4F,/"3"0x66,/"4"0x6D,/"5"0x7D,/"6

2、"0x07,/"7"0x7F,/"8"0x6F,/"9"0x77,/"A"0x7C,/"B"精心整理0x39, /"C"0x5E, /"D"0x79, /"E"0x71, /"F" void delay() /5us;void delay1(uint z)/1msuint x,y; for(x=z;x>0;x-) for(y=120;y>0;y-);void display(uchar valu

3、e)uchar bai,shi,ge; bai=value/100; shi=value%100/10; ge=value%100%10;dula=1;P0=tablebai;dula=0;P0=0xff; 精心整理精心整理wela=1;P0=0xfe; wela=0; delay1(1);dula=1;P0=tableshi;dula=0;P0=0xff; wela=1;P0=0xfd; wela=0;delay1(1);dula=1;P0=tablege;dula=0;P0=0xff;wela=1;P0=0xfb; wela=0;delay1(1);void start()精心整理精心整理

4、scl=1;_nop_();sda=1; delay();sda=0; delay();scl=0;_nop_();void stop()scl=1;_nop_();sda=0; delay();sda=1; delay();void respons()scl=1;_nop_();sda=0; 精心整理精心整理 delay(); scl=0; _nop_();void norespons() scl=1;_nop_(); sda=1;delay(); void init()scl=1;_nop_(); sda=1;_nop_();void write_byte(uchar dat)uchar

5、i,temp;temp=dat;for(i=0;i<8;i+)精心整理精心整理scl=0;_nop_();if(temp&0x80)=0x80) sda=1; / 1elsesda=0; / 0scl=1;_nop_();temp<<=1;scl=0;_nop_();uchar read_byte()uchar dat,i;sda=1;_nop_();scl=0;_nop_();for(i=0;i<8;i+) 精心整理精心整理scl=1; _nop_();if(sda)dat|=0x01; if(i<7)dat<<=1; scl=0;_nop_

6、();return dat;void DAC_write(uchar dat)start();write_byte(0x90);respons();write_byte(0x40);respons();write_byte(dat);respons();stop();uchar ADC_read(uchar com)精心整理精心整理uchar dat;dat=com;start(); write_byte(0x90); respons(); write_byte(com); respons();start(); write_byte(0x91); respons(); dat=read_byte();norespons(); stop(); return dat;void main()uchar i=0,ad_va