adc.c

用SL811做USB主机的源码

/*
;********int The adc***********
;configure channel CH5,CH4(p1.5,p1.4) for adc		<------adcf=30h=00110000b
;The adc Clock is 500K=Fcpu/(4*(adclk+1))=40M/80	<------adclk
;setb	ADEN(enable adc)				<------adcon=20h
;adcon=25h+8 means "configure the p1.5 and start adc"
;adcon=24h+8 means "configure the p1.4 and start adc"
;The result of 8 bits is ADDH
;The result of 10 bits is ADDH<<2+ADDL
*/
void int_adc()
{	ADCF=0x30;
	ADCLK=19;
	ADCON=0x20;
}

void adc_process()
{
	Uint value;
	Uchar i;

	switch (state_adc)
	{
		case  0:	P1_2=0;P1_0=1;P1_3=0;P1_1=0;state_adc++;break;
		case  1:	ADCON=0x65+8;state_adc++;break;		
		case  2:	ADCON=0x20;value=(ADDH<<2)|ADDL;
				
					if (value>=1015)
							{state_adc=0;mov_adc=0;open_adc=1;break;}
					else if (close_adc==1) {state_adc=0;open_adc=0;break;}
						else 	state_adc++;break;
					
		case  3:	P1_2=0;P1_0=1;P1_3=1;P1_1=0;state_adc++;break;
		case  4:	ADCON=0x65+8;state_adc++;break;
		case  5:	ADCON=0x20;value=(ADDH<<2)|ADDL;
					i=adc_cishu-1;
					do { adc_x[i]=adc_x[i-1];i--;}
						while (i>0);
					adc_x[0]=value;					
					P1_2=1;P1_0=0;P1_3=0;P1_1=1;state_adc++;break;
		case  6:	ADCON=0x64+8;state_adc++;break;
		case  7:	ADCON=0x20;value=(ADDH<<2)|ADDL;
					i=adc_cishu-1;
					do { adc_y[i]=adc_y[i-1];i--;}
						while (i>0);
					adc_y[0]=value;
					mov_adc++;
					if (mov_adc==adc_cishu) 
						{close_adc=1;open_adc=0;}
					P1_2=0;P1_0=1;P1_3=0;P1_1=0;state_adc=1;break;
		default:	break;
	};
}

//X轴:39y=950*39-865x<=====>y=(950*39-39*x)/865
//Y轴:835y=925*835-239x<=====>y=(925*835-835*x)/239
Uint average_adc(bit f)
{
	Uchar i;
	Uint x,y;

	x=y=0;

	if (f){
		for (i=0;i<adc_cishu;i++)
			{y=y+adc_y[i];}
		y=y/adc_cishu;
		return((920-y)*49/170);
		}
	else		
		{for (i=0;i<adc_cishu;i++)
			{x=x+adc_x[i];}
		x=x/adc_cishu;
		return((950-x)*39/855);
		}

}