fet120_adc10_12.c

一个基于TI的MSP430的程序设计参考代码

//******************************************************************************
//  MSP-FET430P120 Demo - ADC10 Sample A7, 1.5V, TA1 Trigger Ultra-low Power 
//
//  Description; A7 is sampled 1024/second (32xACLK)with reference to 1.5V. All
//  activity is interrupt driven with proper usage of MSP430 low-power modes, 
//  ADC10 and Vref demonstrated. Timer_A with both TA1/TA0 used in upmode to 
//  drive ADC10 conversion (continuous mode can also be used). Inside 
//  of TA0_ISR software will enable ADC10 and internal reference and 
//  allow > 30us delay for Vref to stabilize prior to sample start. Sample 
//  start is automatically triggered by TA1 every 32 ACLK cycles. ADC10_ISR 
//  will disable ADC10 and Vref and compare ADC10 conversion code. Internal 
//  oscillator times sample (16x) and conversion (13x). If A7 > 0.2Vcc, 
//  P1.0 is set, else reset. Normal Mode is LPM3. 
//  //*An external watch crystal on XIN XOUT is required for ACLK*//	  
//  //*MSP430F1232 or MSP430F1132 Device Required*//
//
//                    +-----(0.9766us)---------\\------------------>+
//    TA0_ISR        TA1      ADC10_ISR             TA0_ISR        TA1
//  -----+------------+------------+-----------\\------+------------+----->  
//   Enable ADC    Trigger ADC  Disable ADC 
//   and Vref                   Compare 
//       +-( >30us--->+                      
//
//
//               MSP430F1232
//            -----------------
//        /|\|              XIN|-  
//         | |                 | 32kHz
//         --|RST          XOUT|-
//           |                 |
//       >---|A7          P1.0 |--> LED
//
//  M.Buccini
//  Texas Instruments, Inc
//  January 2004
//  Built with IAR Embedded Workbench Version: 1.25A
//******************************************************************************

#include  <msp430x12x2.h>

void main(void)
{ 
  WDTCTL = WDTPW + WDTHOLD;             // Stop WDT

  ADC10CTL1 = INCH_7 + SHS_1;           // P3.7, TA1 trigger sample start
  ADC10AE = 0x80;                       // P3.7 ADC10 option select 
  P1DIR |= 0x01;                        // Set P1.0 to output direction
  CCTL0 = CCIE;                         // Enable interrupt
  CCR0 = 32-1;                          // PWM Period 
  CCTL1 = OUTMOD_3;                     // CCR1 set/reset
  CCR1 = 2;                             // CCR1 PWM Duty Cycle	  
  TACTL = TASSEL_1 + MC_1;              // ACLK, up mode
  _BIS_SR(LPM3_bits + GIE);             // Enter LPM3, enable interrupts
}                                            

// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR (void)
{
    ADC10CTL0 &= ~ENC;                  // ADC10 disabled
    ADC10CTL0 = 0;                      //ADC10, Vref disabled completely
    if (ADC10MEM < 0x88)                // ADC10MEM = A0 > 0.2V?
      P1OUT &= ~0x01;                   // Clear P1.0 LED off
    else
      P1OUT |= 0x01;                    // Set P1.0 LED on
}

// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
  ADC10CTL0 = SREF_1 + ADC10SHT_2 + REFON + ADC10ON + ADC10IE; 
  ADC10CTL0 |= ENC;                     //ADC10 enable set
}