I just started playing with the MSP430 with the G2553 chip and am having problems with interrupts. I have the following code just for testing and sometimes pressing the button works and sometimes it doesn't. I thought maybe I had a bad board and replaced it but I still have the same problem. I am beginning to think I am just doing something wrong in the debugging or something. But, here is my code:
#include <msp430g2553.h>
#define LED1 BIT0
int main(void) {
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
BCSCTL1 = CALBC1_1MHZ; //Set DCO to 1Mhz
DCOCTL = CALDCO_1MHZ;
P1OUT=BIT0;
P1DIR=BIT0; //P1.0 (LED) as output)
P1IES |= BIT3; // high -> low is selected with IESx = 1.
P1IFG &= ~BIT3; // To prevent an immediate interrupt, clear the flag for
// P1.3 before enabling the interrupt.
P1IE |= BIT3; // Enable interrupts for P1.3
__enable_interrupt();
P1OUT |= BIT0; //Initially the led will glow
while(1)
{}
return 0;
}
#pragma vector = PORT1_VECTOR //PORT1 interrupt vector name
__interrupt void P1_ISR(void) {
P1OUT ^= BIT0;
P1IFG &= ~BIT3; // clear the interrupt flag
}
So I hit the debug button in CCS 7.4, and it loads to the board. I have a breakpoint at stopping the watchdog timer and a breakpoint at toggling BIT0 in the ISR.
I hit resume at the watchdog timer and start trying the button at P1.3. Maybe 1 out of 10 times I'll hit the breakpoint in the ISR but the rest of the time I get nothing.
I apologize if this is just a really basic and dumb question, but I have Googled everything I can think of and searched the forums and come up with nothing.
Any help is appreciated,
