DA輸出控制LED亮度

1、精心整理#include<reg52.h>#include<intrins.h>#define uchar unsigned char#define uint unsigned intsbit 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,/"

2、;6"0x07,/"7"0x7F,/"8"0x6F,/"9"0x77,/"A"0x7C,/"B"精心整理精心整理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 value)

3、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scl=1;_nop_

4、();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 i,temp;temp=dat;for(i=0

5、;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_();return dat;void DAC_write(u

6、char 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