#include <msp430x11x2.h>

// **********************
// *  Global Variables  *
// **********************

int stage = 0;  	// Tracks the stage (0-1) of cycle.

int speed_reg = 1563; 		// Value used to continuously increment speed register,
					
int cycles = 0;         //will use this as another software counter

// **********
// *  Main  *
// **********

void main (void) {

	BCSCTL1 &= ~(RSEL0 + RSEL1 + RSEL2);	//Sets RSELx bits to 000, slowest speed
	DCOCTL  &= ~(DCO0 + DCO1 + DCO2);	// Sets DCOx bits to 000, slowest speed

	WDTCTL = WDT_MDLY_32;	// WDT 1s interval timer.  This statment
							// is required even though WDT is not implemented

	CCTL0 = CCIE;	// CCR0 interrupt enabled
	TACTL = TASSEL_2 + MC_2;	// SMCLK, contmode.  See TI sample code for description

	P2DIR = 0x1E;	// Init P2.x
	P2OUT = 0x00;	//turn off legs and other outputs
	P2OUT |= 0x18;	// turn off leds (inverse logic)

	CCR0 = speed_reg;	// Set initial timer count register

	__enable_interrupt();	// Enable global interrupts (Start Timer)

	_BIS_SR(LPM0_bits + GIE);	// Enter LPM0 w/ interrupt (Low power standby)

}


// ***************
// *  Functions  *
// ***************


// *****************************************************************************
//
//	Name		:	watchdog_timer
//
//	Description	:	WDT interrupt service routine.  Not currently implemented
//
// *****************************************************************************

#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer (void) {

}	// end void watchdog_timer(void)


// *****************************************************************************
//
//	Name        :	Timer_A3
//
//	Description :	Timer A0 interrupt service routine
//					This function occurs whenever CCR0 register reaches 0.  (This
//					register is then incremented inside the isr)  Executes
//					movement based on global dof flag.  Increments step and stage
//					(if necessary).
//
// ****************************************************************************

#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A3 (void)
{
	CCR0 += speed_reg;	// Reincrement timer
	                        //note that the timer counts down from speed_reg

	//for 0.5 second cycles = 25
	if (cycles==25)
	{
	  cycles = 0;         //this happens at the half second mark
	  if (stage==0)       //checks to see which LED is on and off so it can toggle correctly
	  {
	    // write code to activate Tripod A LED
	    // write code to DEactivate Tripod B LED (inverse logic)
	    stage = 1;      //lets the CPU know it's now has A on and B off
	  }
	  else
	  {
	    // write code to activate Tripod B LED
	    // write code to DEactivate Tripod A LED (inverse logic)
	    stage = 0;      //lets the CPU know that A is off and B is on
	  }
	}
	else
	{
	  cycles = cycles + 1;
	}
} // end of timer_isr