Button interrupt not working in CC430 with RF

[rampadc 29]

Hi, I'm getting a weird problem with a button interrupt while using the RF1A module on a CC430F5137 chip, where the code inside the main loop only works 1 time and never again even though the ISR is being executing and flag (buttonPressed) are being set correctly. I can't find what's wrong and can't proceed to fix the problem.

 

Main.c

extern uint8_t buttonPressed;

uint8_t main(void) {
	WDTCTL = (uint16_t)(WDTPW | WDTHOLD);	/* Stop watch dog timer */

	__disable_interrupt();

	//ACLK = REFO 32768 Hz
	//MCLK = SMCLK = 12 MHz
	//UART 38400
	hal_init430();
	hal_initTimers(); //2Hz timer for alive-LED
	
	uint8_t i;
	for(i = 0; i < 4; i++) printf("Syncing UART\r\n\r\n"); //prep realTerm to display ascii characters 
	
	printf("Initializing RF core\r\n");
	phy_reset(); //set voltage levels, write rf registers, etc.
	phy_enableRX(); //go into RX mode
	printf("RF Core initialized\r\n");
	
	//main while loop
	while(1) {
		if(buttonPressed) {
			__no_operation(); //for debugging
			
			buttonPressed = 0;
			printf("\r\nButton pressed!		main-while-loop\r\n");
			phy_transmit((uint8_t*)TxBuffer, sizeof TxBuffer);
		}
		
		__bis_SR_register(LPM3_bits + GIE);
	}
	
	return 0;
}

isr.c 

extern uint8_t buttonPressed;		//hal.c

/*************************************************************************************
 * 				MSP430 Core Interrupts
 *************************************************************************************/
#pragma vector=PORT1_VECTOR
__interrupt void PORT1_ISR(void) {
	switch(__even_in_range(P1IV, 16))
	{
	case  0: break;
	case  2: break;                         // P1.0 IFG
	case  4: 		                        // P1.1 IFG
		P1IFG &= ~BIT1;
		__delay_cycles(24000);				// 2ms debounce delay
		
		//button is active low
		if((P1IN & BIT1) == 0x00) {
			//button is pressed down, transmit "Hello World"
			printf("\r\nButton is pressed 		Line 39 isr.c\r\n");
			buttonPressed = 1;
		}
		__bic_SR_register_on_exit(LPM3_bits); 	//Exit active
		break;
	case  6: break;                         // P1.2 IFG
	case  8: break;                         // P1.3 IFG
	case 10: break;                         // P1.4 IFG
	case 12: break;                         // P1.5 IFG
	case 14: break;                         // P1.6 IFG
	case 16:                                // P1.7 IFG         
		break;
	}
}

UART log for RF project

[oPossum 1,083]

phy_transmit() may be changing low power mode. Search that code or step through it in the debugger and look for any changes to the LPM bits.

[greeeg 460]

I notice that buttonPressed is defined in hal.c

 

Are you defining buttonPressed as volatile? If not, the compiler may be optimising it into a register, so when it is chnaged in the ISR context, the register isn't updated from memory in the main loop context.

[rampadc 29]

Found a misbehaving while loop in phy_transmit(). Thanks for the help guys.