msp430 anoyatron

annoyatron

#include "msp430g2211.h"
			
		
#define PIEZO BIT6
#define LED1 BIT0
		
	
		
unsigned short lfsr = 0xACE1u;			
unsigned int getRnd (void);
void playSound (void);
void playRattle(void);

int i=0;
int j=0;
void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P1DIR |= PIEZO + LED1;                            // P1.5 output
  CCTL0 = CCIE;                             // CCR0 interrupt enabled
  CCR0 = 32767;
  TACTL = TASSEL_1 + MC_1;                  // ACLK, upmode
  P1OUT = 0x00;
  unsigned int delay = 5;
  while(1)
  {
    if (i>delay)
    {
	  playRattle();
	  playSound();
      i=0;
      delay = getRnd() >> 8; // for a resonable amount this "should" be 7
    }
    _BIS_SR(LPM3_bits + GIE);
                     // Enter LPM3 w/ interrupt
  }
}

// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
i++;
 // P1OUT ^= LED1; // this is for testing
_BIC_SR_IRQ(LPM3_bits);
}

unsigned int getRnd () {
  lfsr = (lfsr >> 1) ^ (-(lfsr & 1u) & 0xB400u);    
  return lfsr;
}	

void playRattle(void) {
	  for ( j = 0; j < 25; j++) {
      P1OUT ^= PIEZO;                            // Toggle P1.5
      long z = 1300;                            // Delay
      do (z--);
      while (z != 0);
      P1OUT ^= PIEZO;
      }		
}

void playSound(void) {
	  for ( j = 0; j < 8000; j++) {
      P1OUT ^= PIEZO;                            // Toggle P1.5
      long z = 2;                            // Delay
      do (z--);
      while (z != 0);
      P1OUT ^= PIEZO;
      }		
}