#include <msp430x44x.h>
#include "lcd.h"
#include "delay.h"

 float CDEG, FDEG, XIN,Y, DKEL;
 float XIN7 = 297.7, XIN6 = 297.7, XIN5 = 297.7;
 float XIN4 = 297.7, XIN3 = 297.7, XIN2 = 297.7, XIN1 = 297.7;
 
 // Past values of the filter are  initalized for deg C = 24.5 (corresponds to 297.7 
 // filter value), as a nominal starting temperature. This number comes about by the expression:
 // deg K = deg C + 273.2 or (24.5 + 273.2) = 297.7.  After the filter has gone through
 // 8 iterations (4 for 4th order) for these values, plus another for the actual current deg C, the reading 
 //  will be fairly settled to the actual temperature.  wlg
 
 const float A = 0.613, B = 0.2;       // note that A has been changed from 0.0613 to 0.613
void main(void)
{ 
  // clock config
  WDTCTL = WDTPW + WDTHOLD;             // Stop WDT

  // set up Basic Timer
  IE2 |= BTIE;                            // Enable BT interrupt
  BTCTL = BT_ADLY_2000 | BT_fLCD_DIV256;  // 128 Hz LCD, 2s Interrupt       

  // set up ADC
  ADC12IE |= 0x0040;                 // Enable ADC6 interrupt
  ADC12CTL0 = ADC12ON + REF2_5V + REFON;          // Aref = 2.5V, Aref on
  ADC12CTL1 = CSTARTADD_6 + ADC12SSEL_1 + SHP;        // ADCCLK = ACLK, pulse mode;
  ADC12MCTL6 = SREF_1 + INCH_6;         // Select sixth reg, Aref on, Aref = Vref+,Avss
  ADC12CTL0 |= ENC ;
  
  //set port pins
                        //set P6.6/A6 as input
  P6SEL |= BIT6;                        //select adc function

  //call lcd func
  setupLCD();

   // Enable interrupts and go to sleep forever
  _EINT();                              // Enable interrupts
 // _BIS_SR(LPM3_bits);                   // Enter LPM4
  while(1);                             // NOP
}

// Basic Timer interrupt service routine
interrupt[BASICTIMER_VECTOR] void basic_timer(void) {

     ADC12CTL0 |= ADC12SC;   // start conversion
}

 // ADC interrupt service routine
interrupt[ADC_VECTOR] void adc(void) {

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

  //  The following code combines code writen by
  //  Matt Mahin of UNF to get display output for the 
  //  AD590 Analog Device temperature sensor.
  //  This code will work for deg F up to 199.  For
  //  deg F of 200 and greater, modifications need to
  //  be made on handling the display.  A separate lcd
  //  file is developed for this case: It is;  senhi.c
  //  Prepared by W. L. Green ECE Department, University
  //  of Tennessee;  April, 2006

    XIN = A*B*ADC12MEM6;
      
  //  The sensor signal is brought in on the A to D
  // converter at ADC12MEM6;
  
    
  // A is a scale factor (0.163) that takes the input from the A/D
  // and produces a number on the display that corresponds to the 
  // input to the A/D.
  
  // B is a scale factor the is the recipal of the gain of the op amp
  // used to raise the sensor output voltage.  In my case an op amp gain
  // of 5 was used.  Therefore, B = 0.2.
       
  //  Filter the signal with a 4th order moving average
  //  filter.   
         
    DKEL = (XIN + XIN1 + XIN2 + XIN3)*0.25;    // DKEL is deg Kelvin
         
     XIN3 = XIN2;                              // Update the coefficients of the filter
     XIN2 = XIN1;
     XIN1 = XIN;    
           
      
      
   CDEG = (DKEL - 273.2);            // converting from Kelvin to deg C
                                     // In this case DKEL is the sensor reading
                                     // in deg K.
   FDEG =  1.8*CDEG + 32.0;          // converting from deg C to deg F
   
   lcd_word(100*CDEG, 2);            // the l00 causes the first 3 digits of CDEG
                                     // to be displayed. The 2 causes a decimal
                                     // to be placed to the left of the second display
                                     // slot. 
                                    
   //lcd_char(1,' ');               // The 1 corresponds to the second position from
                                    // the right on the display.  The ' ' places a 
                                    // space in this position.  Take out if you want
                                    // a number in this position.  Play with it and see what
                                    // happens.
                                    
   lcd_char(0,'C');                 // The 0 corresponds to the first position on the
                                    // right side of the display.  The 'C' causes a C
                                    // to be displayed in this position
                                    
   wait_ms(2000);                   // Waits 2000 milliseconds then displays deg F
   
   lcd_word(100*FDEG, 2);           // The l00 causes the first 3 digits of FDEG to be displayed.
                                    // The 2 moves the decimal to the left of the 2nd position.
                                    
   //lcd_char(1,' ');               // See the above statement
   
   lcd_char(0, 'F');                // See the above statement
   
   wait_ms(2000);                   // Wait 2000 milliseconds.  The program then moves
                                    // back to lcd_word(100*CDEG, 0) and continues as a loop
                                   
  }