Other Parts Discussed in Thread: MSP430G2553
Hello,
I'm working with the TI example code for the MSP430G2553 internal temperature sensor. I'm not sure how to read the temperature. I have created a IAR project with the following example code. But when I have launched and run it, the code hangs and the IntDegF and IntDeg are 0 or unavailable. I have read that other people had also problem with this code http://e2e.ti.com/support/microcontrollers/msp430/f/166/t/199435.aspx. Can someone please tell me how to read the temperature values? Further, in the example code, long is used for the variables. Due to application specific requirements I can only use one byte to store the temperature value. Do I have to change the code? Thanks a lot!
#include <msp430.h>
long temp;
long IntDegF;
long IntDegC;
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
ADC10CTL1 = INCH_10 + ADC10DIV_3; // Temp Sensor ADC10CLK/4
ADC10CTL0 = SREF_1 + ADC10SHT_3 + REFON + ADC10ON + ADC10IE;
__enable_interrupt(); // Enable interrupts.
TACCR0 = 30; // Delay to allow Ref to settle
TACCTL0 |= CCIE; // Compare-mode interrupt.
TACTL = TASSEL_2 | MC_1; // TACLK = SMCLK, Up mode.
LPM0; // Wait for delay.
TACCTL0 &= ~CCIE; // Disable timer Interrupt <- code hangs here
__disable_interrupt();
while(1)
{
ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start
__bis_SR_register(CPUOFF + GIE); // LPM0 with interrupts enabled
// oF = ((A10/1024)*1500mV)-923mV)*1/1.97mV = A10*761/1024 - 468
temp = ADC10MEM;
IntDegF = ((temp - 630) * 761) / 1024;
// oC = ((A10/1024)*1500mV)-986mV)*1/3.55mV = A10*423/1024 - 278
temp = ADC10MEM;
IntDegC = ((temp - 673) * 423) / 1024;
__no_operation(); // SET BREAKPOINT HERE
}
}
// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR (void)
{
__bic_SR_register_on_exit(CPUOFF); // Clear CPUOFF bit from 0(SR)
}
#pragma vector=TIMER0_A0_VECTOR
__interrupt void ta0_isr(void)
{
TACTL = 0;
LPM0_EXIT; // Exit LPM0 on return
}
