msp430x20x2 adc10 temp

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

//****************************************************************************** // 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

//

-// /|\|

XIN|-// | | |

// |RST

XOUT|-// | |

// |A10 |

//

// 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(); // 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

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

}