//*****************************************************************************
//  MSP-430-Day II Demo - ADC12 Sample A10 Temp Set P1.0 if temp ++ ~2c 
//
//  Description: Use ADC12 and the integrated temperature sensor to detect
//  temperature gradients. The temperature sensor output voltage is sampled
//  ~ every 80ms and compared with the defined delta values using an ISR.
//  (ADC12OSC/256)/ determines sample time which needs to be greater than 
//  30us for temperature sensor. 
//  ADC12 is operated in repeat-single channel mode with the sample and 
//  convert trigger sourced from Timer_A CCR1. The ADC12MEM)_IFG at the end
//  of each converstion will trigger an ISR.
//  ACLK = 32768, MCLK = SMCLK = default DCO =1048576, ADC12CLK = ADC12OSC
//  //*An external watch crystal on XIN XOUT is required for ACLK*//	  
//  //*MSP430FG439 Device Required*//
//
//                MSP430FG439
//            -----------------
//        /|\|              XIN|-  
//         | |                 | 32KHz
//         --|RST          XOUT|-
//           |                 |
//           |A10          P1.0|-->LED
//
//  M. Buccini
//  Texas Instruments Inc.
//  February 2004
//  Built with IAR Embedded Workbench Version: 2.21B
//*****************************************************************************
#include <msp430xG43x.h>

#define ADCDeltaOn       12                           // ~2 Deg C delta

static unsigned int FirstADCVal;                      // holds 1st ADC result

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                           // Stop watchdog
  FLL_CTL0 |= XCAP14PF;                               // Set load capacitance
  P1OUT = 0x00;                                       // Clear P1
  P1DIR = 0x01;                                       // P1.0 = output
  ADC12CTL1 = SHS_1 + SHP + CONSEQ_2;                 // TA trig., rpt conv.
  ADC12MCTL0 = SREF_1 + INCH_10;                      // Channel A10, Vref+
  ADC12IE = 0x01;                                     // Enable ADC12IFG.0          
  ADC12CTL0 = SHT0_8 + REF2_5V + REFON + ADC12ON + ENC;  // config ADC12
  TACCTL1 = OUTMOD_4;                                 // Toggle on EQU1 (TAR = 0)
  TACTL = TASSEL_2 + MC_2;                            // SMCLK, cont-mode
  while (!(0x01 & ADC12IFG));                         // First conversion?
  FirstADCVal = ADC12MEM0;                            // Read out 1st ADC value
  _BIS_SR(LPM0_bits + GIE);                           // Enter LPM0 w/ interrupt
}

#pragma vector=ADC_VECTOR
__interrupt void ADC12ISR (void)
{
  if (ADC12MEM0 <= FirstADCVal + ADCDeltaOn)
      P1OUT &= ~0x01;                         	      // LED off
  else P1OUT |= 0x01;                                 // LED on
}