msp430I2031: denouncing key

Hi Hiren,

try the Code Composer Studio Resource Explorer for device specific Code Examples.

This is written for FR5969 - so you might have to adjust ports. This code toggles the Port 4.6 LED1 on when Button1 on Port 4.5 is pressed and off when released.

I have not had any bouncing issues with this. Otherwise you could set a minimum debouncing time and compare it with a timer each time your Interrupt is called.

For further information try: www.ganssle.com/debouncing-pt2.htm

#include <msp430.h>
void InitializePins(void);
int main(void)
{
  WDTCTL = WDTPW | WDTHOLD;                 // Stop WDT
  PM5CTL0 &= ~LOCKLPM5;

  InitializePins();

  __bis_SR_register(LPM0_bits + GIE);       // Enter LPM0 w/ interrupt
  __no_operation();                         // For debugger
}
void InitializePins(void)
{
    P4DIR &= 0x00;
    P4OUT &= 0x00;
    P4DIR |= (BIT5 + BIT6);         // as output
    P4OUT |=  BIT5;                 // pull-up mode
    P4REN |= BIT5;                  // pull-up enable
    P4IE |= BIT5;
    P4IES |= BIT5;
    P4IFG &= ~ BIT5;
}
// Timer0_A0 interrupt service routine
#pragma vector = PORT4_VECTOR
__interrupt void Port_4(void)
{
    P4OUT ^= BIT6;
    P4IES ^= BIT5;          // Toggles rising + falling Edge
    P4IFG &= ~BIT5;
}