msp430x20x2 adc10 temp

//******************************************************************************
// MSP430F20x2 Demo - ADC10, Sample A10 Temp and Convert to oC and oF
//
// Description: A single sample is made on A10 with reference to internal
// 1.5V Vref. Software sets ADC10SC to start sample and conversion - ADC10SC
// automatically cleared at EOC. ADC10 internal oscillator/4 times sample
// (64x) and conversion. In Mainloop MSP430 waits in LPM0 to save power until
// ADC10 conversion complete, ADC10_ISR will force exit from any LPMx in
// Mainloop on reti. Temperaure in oC stored in IntDegC, oF in IntDegF.
// Uncalibrated temperature measured from device to device will vary with
// slope and offset - please see datasheet.
// ACLK = n/a, MCLK = SMCLK = default DCO ~1.2MHz, ADC10CLK = ADC10OSC/4
//
//
//

MSP430F20x2
-----------------

//

/|\|

//

||

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//

--|RST

XOUT|-

//

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//

|A10

XIN|-

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//
// L. Westlund
// Texas Instruments Inc.
// May 2006
// Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A


//******************************************************************************
#include "msp430x20x2.h"

long temp;
long IntDegF;
long IntDegC;

void 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();
TACCR0 = 30;
TACCTL0 |= CCIE;

// Enable interrupts.
// Delay to allow Ref to settle
// Compare-mode interrupt.

TACTL = TASSEL_2 | MC_1;
LPM0;

// TACLK = SMCLK, Up mode.
// Wait for delay.

TACCTL0 &= ~CCIE;

// Disable timer Interrupt

__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=TIMERA0_VECTOR
__interrupt void ta0_isr(void)
{
TACTL = 0;
LPM0_EXIT;
}

// Exit LPM0 on return