#include <stdarg.h>
#include <stdio.h>
#include <msp430x20x2.h>


int UART_printf(const char *format, ...);
//unsigned int ADC[4];
unsigned int ADC[4];
unsigned int Pos_ADC;
unsigned int Vel_ADC;

char newprint = 0;
long timeint = 0;
int freq = 4800;  // Print to UART every .5 seconds


void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  DCOCTL = CALDCO_16MHZ;                    // Set uC to run at approximately 16 Mhz
  BCSCTL1 = CALBC1_16MHZ; 
  P1DIR |= 0xFF;                            // P1.0 and P1.7 outputs
  
  CCTL0 = CCIE;                             // CCR0 interrupt enabled
  CCR0 = 1653;                              // 1653 is 1/9600 seconds sets up timer for output only UART baud rate of 9600.   
  TACTL = TASSEL_2 + MC_2;                  // SMCLK, contmode
  
  ADC10CTL1 = INCH_1 + ADC10SSEL_3 + CONSEQ_1; //INCH_1: block convert will capture channels 1 and 0 in that order.
  ADC10CTL0 = ADC10ON + MSC + ADC10IE;
  								 																							    
  
  ADC10AE0 |= 0x03;                            // P1.1,0 ADC10 option select.

  ADC10DTC1 = 2;			       // Two conversions.
  ADC10SA = (short)&ADC[0];                    // ADC10 data transfer starting address.
  ADC10CTL0 |= ENC + ADC10SC;				   // Sampling and conversion start.
  
  //_BIS_SR(LPM0_bits + GIE);				   // LPM0, ADC10_ISR will force exit.
  _BIS_SR(GIE);                             // Enable global interrupt

  
  while(1) {
    if (newprint == 1)  { // newprint set to one in timer ISR
      
//      P1OUT ^= 0x01;  // toggle P1.0 on and off
      Pos_ADC = ADC[1];
      Vel_ADC = ADC[0];
              
      UART_printf("Digi %d %d\n\r",Pos_ADC,Vel_ADC);  // Print to UART

      //UART_printf("YESa \n\r ");  // Print to UART
      newprint = 0;  // reset flag back to zero
      
    }
  }     
}


//ADC10 interrupt Service Routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR (void) {
  ADC10CTL0 &= ~ADC10IFG;
  ADC10SA = (short)&ADC[0];                    // ADC10 data transfer starting address.
  ADC10CTL0 |= ENC + ADC10SC;				   // Sampling and conversion start.

}


// only 15 characters can be sent at a time
#define UART_PRINTF_SIZE 15
char txbuff[UART_PRINTF_SIZE];  // global character buffer set in the function UART_printf and the output in the timer ISR function Timer_A
signed char txcount = 0;   // variables used to "Bit-Bang" the UART output transmission.
signed char currentbit = -1;
signed char currentindex = 0;
signed char senddone = 1;


// This function assumes txbuff has already been filled with the characters to send.
// It initializes txcount to the number of chars to send and then sets senddone = 0 so that txbuff is sent out P1.7 in the function Timer_A
int sendchars(int size) {
  
  if (senddone == 1) {  // Only setup txcount if previous transmission complete
    if (size < UART_PRINTF_SIZE) {
      txcount = size;
    } else {
      txcount = UART_PRINTF_SIZE;
    }
 
    currentbit = -1;  // initialize indexes
    currentindex = 0;
    senddone = 0;  // signal that a new transmission should occur.
    return(0);
  } else {
    return(-1); // error
  }
  
}

int UART_printf(const char *format, ...)               
{
  // the "va" and "v" functions handle the variable argument ... in the function parameters
  va_list ap;
  int error;
  
  va_start(ap, format);      /* Variable argument begin */
  error = sendchars(vsprintf(txbuff, format, ap));   // fill txbuff with the format string and the pass the size of txbuff to the sendchars function
  va_end(ap);                /* Variable argument end */
  return error;
}


// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
  CCR0 += 1653;                            // Add Offset to CCR0   because timer 0 has been told to continuously count up.
  if (senddone == 0) {
    if (currentbit == -1) {
      P1OUT &= 0x7F;// start bit
      currentbit++;
    } else if (currentbit == 8) {
      P1OUT |= 0x80; // stop bit
      currentbit = -1;
      currentindex++;
        if (currentindex == txcount) {
          senddone = 1;
        }
    } else {
      if ((txbuff[currentindex]>>currentbit)&0x1) {
        P1OUT |= 0x80;  // char bit is HI
      } else {
        P1OUT &= 0x7F; // char bit is LOW
      }
      currentbit++;
    }
  }  
  timeint++; // Keep track of time for main while loop. This is incrementing even when characters are not being sent out 
  
  if ((timeint%freq) == 0) {
    newprint = 1;  // flag main while loop that "freq: number of ticks have gone by.  
  }
}