MotorController

/*
 * MotorController by James Trimble, Capt, USAF
 * USAFA ECE Automata Club
 * Description: Uses the Analog-to-Digital Converter to read the voltage from a voltage divider (100K resistor w/ 100K pot).
 * Sets the PWM duty cycle based on the ADC value to allow controlling a DC motor's speed using the potentiometer.
 */

#include <msp430.h> 

int main(void) {
	WDTCTL = WDTPW + WDTHOLD;                   	// Stop WDT
	  ADC10CTL0 = ADC10SHT_3 + ADC10ON + ADC10IE; 	// ADC10ON, interrupt enabled
	  ADC10CTL0 &= ~0xD000;			      			// Use GND to VCC as the reference range (0V to 3.3V)
	  ADC10CTL1 = INCH_4;                         	// input A4
	  ADC10AE0 |= BIT4;                           	// PA.1 ADC option select
	  ADC10CTL1 |= ADC10SSEL1|ADC10SSEL0;         	// Select SMCLK

	  P1DIR |= BIT0;                              	// Set P1.0 to output
	  P1DIR |= BIT6;             				  	// P1.6 to output
	  P1DIR |= BIT2;             				  	// P1.2 to output
	  P1SEL |= BIT2;             				  	// P1.2 to TA0.1 (Tie P1.2 to the Timer output)

	  CCR0 = 0x2C0;             					// PWM Period
	  CCTL1 = OUTMOD_7;          					// CCR1 reset/set
	  CCR1 = 0x2;                					// CCR1 PWM duty cycle
	  TACTL = TASSEL_2 + MC_1;   					// SMCLK, up mode

	  for (;;)
	  {
		ADC10CTL0 |= ENC + ADC10SC;               	// Sampling and conversion start
		CCR1 = ADC10MEM;							// Set the PWM Duty Cycle to the ADC Value
		__bis_SR_register(CPUOFF + GIE);          	// LPM0, ADC10_ISR will force exit

	  }

	  return 0;
}

// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR(void)
{
  __bic_SR_register_on_exit(CPUOFF);          // Clear CPUOFF bit from 0(SR)
}