DA输出控制LED亮度

1、#define uchar unsigned char#define uint unsigned intsbit sda=P2A0;sbit scl=P2Al；sbit dula=P2A6;sbit wela=P2A7;uchar code table=0x3F, /00x06, /10x5B, /20x4F, /30x66, /40x6D, /50x7D, /60x07, /70x7F, /80x6F, /90x77, /A0x7C, /B0x39, /C0x5E, /D0x79, /E0x71, /F;void delay() /5us;void delay1(uint z)/1msuin

2、t x,y;for(x=z;x0;x-)for(y=120;y0;y-);void display(uchar value)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

3、=0xfb;wela=0;delay1(1);void start()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;delay();scl=0;_nop_();void norespons()scl=1;_nop_();sda=1;delay(); void init()scl=1;_nop_();sda=1;_nop_();void write_byte(

4、uchar dat)uchar i,temp;temp=dat;for(i=0;i8;i+)scl=0;_nop_();if(temp&0x80)=0x80)sda=1; / a 1 elsesda=0; / aO scl=1;_nop_();temp=1;scl=0;_nop_();uchar read_byte() uchar dat,i;sda=1;_nop_();scl=0;_nop_();for(i=0;i8;i+)scl=1;_nop_();if(sda)dat|=0x01;if(i7)dat=1;scl=0;_nop_();return dat;void DAC_write(uc

5、har 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()uchar i=0,ad_value;