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=PSO;sbit scl=P 2八1;sbit dula=卩2八6;sbit wela二卩2八7;uchar code table=Ox3F,/"O"OxO6,/"1"Ox5B,/"2"Ox4F,/"3"Ox66,/"4"Ox6D,/"5"Ox7D,/&

2、quot;6"OxO7,/"7"Ox7F,/"8"Ox6F,/"9"Ox77,/"A"Ox7C,/"B"Ox39,/"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 va

3、lue)uchar bai,shi,ge;bai=value/100;shi=value%100/10;ge=value%100%10;dula=1;P0=tablebai;dula=0;P0=0xff;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()scl=1;_nop_();sda=1;del

4、ay();sda=0;delay();scl=0;_nop_();void stop()scl=1;_nop_();sda=0;delay();sda=1;delay();void respons()scl=1;_nop_();sda=0;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;i<8;i+)scl=0;_no

5、p_();if(temp&0x80)=0x80)sda=1; / g1elsesda=O; / g0scl=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+)scl=1;_nop_();if(sda)dat|=0x01;if(i<7)dat<<=1;scl=0;_nop_();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)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()ucha