test44x_ca04.c

430例程大全 端口操作 时钟模块FLL+操作 flash读写操作 看门狗操作 timerA-操作 timerB-操作 比较器A操作 基本定时器LED&LCD操作 ADC&BT&LC

#include  "msp430x44x.h"


void main (void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P5OUT &= ~0x02;                           // P5.1 reset
  P5DIR |= 0x02;                            // P5.1 output direction
  P1OUT &= ~(Ref + Sensor);                 // Ref set
  P1DIR |= Ref + Sensor;                    // Ref output
  CACTL1 = CARSEL + CAREF0 + CAON;          // -Comp = 0.25*Vcc - on
  CACTL2 = P2CA0;                           // +Comp = 1.6
  TACTL = TASSEL_2 + MC_2;                  // SMCLK, clear TAR
  _EINT();                                  // Enable interrupts
  
  while (1)                                 // Mainloop
  {
     sensor_time = measure(Sensor);         // Measure discharge time through sensor
     ref_time = measure(Ref);               // Measure discharge time through Ref
     if (sensor_time < ref_time)            // if sensor time < ref time ( >25c )
      P5OUT |= 0x02;                        // LED on - Set P5.1
     else P5OUT &= ~0x02;                   // LED off - Reset P5.1
  }
}

unsigned int measure(int source) {            
  P1OUT |= Ref;                             // Ref Set
  P1DIR |= Ref;                             // Ref output
  CCR1 = TAR + 5000;                        // CCR1 ~ TAR+5ms
  CCTL1 = CCIE;                             // Comp,interrupt
  LPM0;                                     // Wait for CCR1 interrupt
  P1DIR &= ~Ref;                            // Ref = HiZ, Charge complete
  P1OUT &= ~Ref;                            // Ref = Reset
  CCTL1 = CM_2 + CCIS_1 + CAP + CCIE;       // Neg, CCIB,Cap,interrupt
  timer_count = TAR;                        // TAR at before discharge
  P1DIR |= source;                          // Temp = Sensor or Ref
  LPM0;                                     // Wait for CCR1 interrupt
  timer_count = CCR1 - timer_count;         // timer_count = discharge time
  P1DIR &= ~(Sensor + Ref);                 // Disable Sensor or Ref
  CCTL1 = 0x00;                             // Disable CCTL1
  return(timer_count);
} 

// Timer A1 interrupt service routine
interrupt[TIMERA1_VECTOR] void Timer_A(void)
{
 switch( TAIV )
 {
   case  2: LPM0_EXIT;                      // ccr1
            break;
 }
}