MSP430F2274

/* --COPYRIGHT--,BSD_EX
 * Copyright (c) 2012, Texas Instruments Incorporated
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * *  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * *  Neither the name of Texas Instruments Incorporated nor the names of
 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *******************************************************************************
 * 
 *                       MSP430 CODE EXAMPLE DISCLAIMER
 *
 * MSP430 code examples are self-contained low-level programs that typically
 * demonstrate a single peripheral function or device feature in a highly
 * concise manner. For this the code may rely on the device's power-on default
 * register values and settings such as the clock configuration and care must
 * be taken when combining code from several examples to avoid potential side
 * effects. Also see www.ti.com/grace for a GUI- and www.ti.com/msp430ware
 * for an API functional library-approach to peripheral configuration.
 *
 * --/COPYRIGHT--*/
//******************************************************************************
//  MSP430F22x4 Demo - ADC10, Sample A11, Lo_Batt, Set P1.0 if AVcc < 2.3V
//
//  Description: A single sample is made on A11 (AVcc/2) with reference to
//  internal 1.5V Vref. Software sets ADC10SC to start sample and conversion
//  - ADC10SC automatically cleared at EOC. ADC10 internal oscillator times
//  sample (16x) and conversion. ADC10BUSY flag is polled for EOC. If A11
//  (AVcc/2) < 0311h (1.15V) indicating AVcc is less 2.3V, P1.0 set indicating
//  a lo_Batt condition, else reset.
//
//                MSP430F22x4
//             -----------------
//         /|\|              XIN|-
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//            |A11 (AVcc/2) P1.0|-->LED
//
//  A. Dannenberg
//  Texas Instruments Inc.
//  April 2006
//  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A
//******************************************************************************
#include <msp430.h>

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  ADC10CTL1 = INCH_11;                      // AVcc/2
  ADC10CTL0 = SREF_1 + ADC10SHT_2 + REFON + ADC10ON;
  TACCR0 = 30;                              // Delay to allow Ref to settle
  TACCTL0 |= CCIE;                          // Compare-mode interrupt
  TACTL = TASSEL_2 + MC_1;                  // TACLK = SMCLK, Up mode
  __bis_SR_register(CPUOFF + GIE);          // LPM0, TA0_ISR will force exit
  TACCTL0 &= ~CCIE;                         // Disable timer Interrupt
  P1DIR |= 0x01;                            // Set P1.0 to output direction

  for (;;)
  {
    ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
    while (ADC10CTL1 & ADC10BUSY);          // ADC10BUSY?
    if (ADC10MEM < 0x311)                   // ADC10MEM = A11 > 1.15V?
      P1OUT |= 0x01;                        // Set P1.0 LED on
    else
      P1OUT &= ~0x01;                       // Clear P1.0 LED off
  }
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMERA0_VECTOR
__interrupt void TA0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMERA0_VECTOR))) TA0_ISR (void)
#else
#error Compiler not supported!
#endif
{
  TACTL = 0;                                // Clear Timer_A control registers
  LPM0_EXIT;                                // Exit LPM0 on return
}