Msp430 Launchpad Programming

Question

I have code like this in IAR Embedded Workbench. At least Led0 should blink?

#include <io430.h>
#include<signal.h>

void main(void)
{
  WDTCTL = WDTHOLD + WDTPW; 
  P1DIR = BIT6 + BIT4 + BIT3 + BIT7 + BIT0;
  P1OUT |= BIT6 + BIT4 + BIT3 + BIT7+ BIT0;
}

Answer 1

That won't do anything. You need an infinite loop, a delay, and some way of toggling the output. Something like this should work:

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;             // Stop watchdog timer
  P1DIR |= 0x01;                        // Set P1.0 to output direction

  for (;;)
  {
    volatile unsigned int i;

    P1OUT ^= 0x01;                      // Toggle P1.0 using exclusive-OR

    i = 50000;                          // Delay
    do (i--);
    while (i != 0);
  }
}

Answer 2

#include  "msp430.h"

// set names for bits to improve code readability
#define     LED0                  BIT0
#define     LED1                  BIT6
#define     LED_DIR               P1DIR
#define     LED_OUT               P1OUT


void main (void)
{
    WDTCTL = WDTPW + WDTHOLD;      // halt the watchdog timer

    LED_DIR |= LED0 + LED1;        // set both pins with our two LEDs as ouputs
    LED_OUT &= ~(LED0 + LED1);     // make sure both LEDs are off to begin with

    TACCTL0 = CCIE;                // enable timer interrupt
    TACCR0 = 16384;                // set timer value to count

    // Start timer A0, in UP mode. which counts from 0x0000 to the value
    // in TACCR0, then generate an interrupt.       
    TACTL = TASSEL1 + MC_1;

    // Enter low power mode one, with general interrupts enabled.
    __bis_SR_register(LPM1_bits + GIE);
}

#pragma vector=TIMERA0_VECTOR    // timer A0 interrupt routine
__interrupt void timerA0_isr(void) {
    // Flip the output state of both LEDs.
    // After each interrupt, the state changes, which makes the LEDs blink.
    LED_OUT ^= (LED0 + LED1);
}

You can change timer to make it blink at proper interval. Also if you initially set one led on and the other off, when the interrupt occurs they will blink alternately.