adc.c

#include<msp430.h>

void init_adc()
{
    ADC10CTL0|=ADC10ON|SREF_0|ADC10SHT_2;
	ADC10CTL1|=INCH_4|SHS_0|ADC10DIV_0|ADC10SSEL_0|CONSEQ_0;
	ADC10AE0=BIT4;
	ADC10CTL0|=ENC;
}
void start()
{
	ADC10CTL0|=ADC10SC;
}

int busy()
{
	return ADC10CTL0 & ADC10BUSY;
}

void delay(int i)
{
	while(i--);
}

void pwm(int d)
{
	P1OUT=0x20;
	delay(d);
	P1OUT=0x00;
	delay(1000-d);
}
	
main()
{
	init_adc();
	P1DIR=0x20;
	P1OUT=0x00;
	while(1)
	{
		start();
		while(busy());
		if(ADC10MEM>1000)
			P1OUT=0x20;
		else if(ADC10MEM>950)
			pwm(950);
		else if(ADC10MEM>900)
			pwm(900);
		else if(ADC10MEM>850)
			pwm(850);
		else if(ADC10MEM>800)
			pwm(800);
		else if(ADC10MEM>700)
			pwm(750);
		else if(ADC10MEM>650)
			pwm(700);
		else if(ADC10MEM>600)
			pwm(650);
		else if(ADC10MEM>550)
			pwm(600);
		else if(ADC10MEM>500)
			pwm(550);
		else if(ADC10MEM>450)
			pwm(500);
		else if(ADC10MEM>400)
			pwm(450);
		else if(ADC10MEM>350)
			pwm(400);
		else if(ADC10MEM>300)
			pwm(350);
		else if(ADC10MEM>250)
			pwm(300);
		else if(ADC10MEM>200)
			P1OUT=0x00;
		delay(1000);
	}
}