单片机入门系列

单片机入门系列-avrAD转换程序〃本例使用内部参考电压，ADc0输入，采集的信号通过LED显示。〃整理：AVR与虚拟仪器古欣//ICC-AVRapplicationbuilder:2006-9-311:42:36//Target:M32//Crystal:7.3728Mhz//2.56v片内基准电压，输入a1:即adc0//误差为：连续测量模式。//精度8，输出左对齐ADLAR=1//注意：参考电压一定要高于被测电压。#include<iom32v.h>#include<macros.h>〃数字滤波#definea0xF4//a=0.95#defineb0x0D//b=1-a=0.05constled_table[16]={0xa0,0xfc,0xc1,0xd0,0x9c,0x92,0x82,0xf8,0x80,0x90,0x88,0x86,0xc7,0xc4,0x83,0x8b};//0~~ftypedefunsignedcharuint8;uint8value,value1=0;intx;//最终的值10位volatileuint8i,j=0;//delayvoidDelay100us(uint8n){uint8i;for(i=36;n!=0;n--)while(--i);}voidDelay1s(uint8n){n=n*10;for(;n!=0;n--){Delay100us(200);}}voidport_init(void){PORTA=0x00; 〃做adc输入时不可上拉。DDRA=0x00;PORTB=0xFF;DDRB=0xFF;PORTC=0xFF;DDRC=0x00;PORTD=0xFF;DDRD=0x00;}//ADCinitialize//Conversiontime:225uSvoidadc_init(void){ADCSR=0x00;//disableadcADMUX=0xC0|(1<<ADLAR);//2.56v片内基准电压/selectadcinput0/ACSR=0x80;//使能adc可用，不用修改ADCSRA=0xA8;//ADC使能，自动触发模式使能，触发源由SFIOR确定，中断使能，分频因子为2SFIOR=0X60;//触发源设置为：定时器比较匹配}//TIMER0initialize-prescale:1024//WGM:Normal//desiredvalue:1Hz//actualvalue:35.556mSec(-3455.6%)voidtimer0_init(void){TCCR0=0x00;//stopTCNT0=0x01;//setcountOCR0=0x02;//setcompare//FFTCCR0=0x0D;//starttimer1024分频CTC比较输出定时时间：256/(7.3728Mhz/1024)=35.556ms}#pragmainterrupt_handlertimer0_ovf_isr:10voidtimer0_ovf_isr(void){TCNT0=0x01;//reloadcountervaluej++;if(j==0)CLI();#pragmainterrupt_handlertimer0_comp_isr:20voidtimer0_comp_isr(void){//compareoccuredTCNT0=OCR0TCNT0=0x01;//reloadcountervaluei++;if(i==0)CLI();}#pragmainterrupt_handleradc_isr:15voidadc_isr(void){//conversioncomplete,readvalue(int)using...//ADIF硬件清零ADCSRA|=(1<<ADIF);//ADIF置1清位value=ADCH;//Read8lowbitsfirst(important)//value|=(int)ADCH<<8;//read2highbitsandshiftintotopbyt//value=(value*2.56)/1024;〃数字滤波value1=(char)(((int)a*value1+(int)b*value)>>8);//value1=(int)(a*value1+b*value);x=0|value1;x=x<<2;//真实的10位值if(((x/100)<16)&&((x/100)>0))PORTB=led_table[x/100];elsePORTB=led_table[0];/*/测试j++;if(j==255){//TIMSK=0x00;ADCSRA&=~(1<<ADIE);CLI();PORTB=led_table[0];}*/}//callthisroutinetoinitializeallperipheralsvoidinit_devices(void){//stoperrantinterruptsuntilsetupCLI()一—disab-eOJ--mr-t-erruprsporrm一5ir-f--me「o——m-r-t-(*adc—m-oiMCUCRH0X00-=KIGICRHoxooi^boor-t-禅翅TIMSKHOXOYWmer-nrerrupr-t-sourcesSEI()i/>e—enab-e5'r-f-errupr-f-sda=per-phe「a-sarenow-n-<-f-Q5'=zed)voidmam(vo.d)nk——de<.ces(*ADCSRA