Other Parts Discussed in Thread: MSP430G2553
Hi,
I am using the MSP430G2553 launchpad and am trying to write a code that continuously checks the comparator input CA1 with the reference (0.5 VCC). If the CA1 is higher than the reference the on board Green LED (P1.6) turns on for 2400 cycles (200ms as I am using the VLO).
It looks like there is some issue with the 'if' condition in the pragma vector block. It looks like the interrupt is detected every time the voltage on Pin 1.1 crosses the reference,and the value of the CAOUT in the CACTL2 register also changes correctly. However, the green LED stays on once turned on regardless of the input at CA1. I would appreciate any feedback on this.
Here is the code:
#include <msp430g2553.h>
#ifndef TIMER0_A1_VECTOR
#define TIME0_A1_VECTOR TIMERA1_VECTOR
#define TIMER0_A0_VECTOR TIMER0_VECTOR
#endif
void registerFault(void);
void clockConfig(void);
void configPins(void);
void comparatorSetup(void);
/*
* main.c
*/
void main(void) {
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
clockConfig();
configPins();
comparatorSetup();
while(1)
{
_bis_SR_register(LPM3_bits + GIE);
}
}
void registerFault(void)
{
P1OUT = BIT0;
while(1);
}
void clockConfig(void)
{
if (CALBC1_1MHZ ==0xFF || CALDCO_1MHZ == 0xFF)
registerFault(); // If calibration data is erased
// run FaultRoutine()
BCSCTL1 = CALBC1_1MHZ; // Set range
DCOCTL = CALDCO_1MHZ; // Set DCO step + modulation
BCSCTL3 |= LFXT1S_2; // LFXT1 = VLO select VLO as low freq clock
IFG1 &= ~OFIFG; // Clear OSCFault flag
BCSCTL2 |= SELM_0 + DIVM_3 + DIVS_3; // MCLK = DCO/8, SMCLK = DCO/8
TACTL = TASSEL_1 + MC_2; //Configure timer A for ACLK and continuous mode
}
void configPins(void)
{
P1DIR = ~BIT1;
P1OUT = 0;
}
void comparatorSetup(void)
{
CACTL1 = CAREF_2 + CARSEL + CAIE;
CACTL2 = P2CA4 + CAF;
CAPD = CAPD1;
CACTL1 |=CAON;
}
#pragma vector = COMPARATORA_VECTOR
__interrupt void COMPA_ISR(void)
{
if((CACTL2 & CAOUT)==0x01)
{
P1OUT=BIT6;
_delay_cycles(2400);
}
else
{
P1OUT=0;
}
}
