main.c

是MSP430F2274的源代码

#include "msp430x22x4.h"
//OA0工作在模式2(unity gain)
//p2.0为正端输入
//p2.1输出(最大输AVCC)
//将输入电压的地接到芯片的AVss
//用OAFBR来选择反馈电阻值
//将直流电源正端接入p2.0,调节电压值,观参输出是否跟输入保持一致
//                 MSP430F2274
//             -----------------
//         /|\|              XIN|-  
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//            |             P2.0|<--OA0I0
//            |             AVss|<--GND
//            |             p2.1|-->OA0O     
int main( void )
{
  WDTCTL=WDTPW+WDTHOLD;                   //关看门狗
  BCSCTL1 =CALBC1_1MHZ;                   //设定DCO为1MHZ
  DCOCTL =CALBC1_1MHZ;
  P2SEL |=BIT0+BIT1;                      //P2.0,2.1第二功能选择
  P2OUT |=BIT1;                           //p2.1,OA0输出端(不加也没关系)                         
  
  OA0CTL0=OAP_0+OAPM_3+OAADC1;            //OAP选择OA0I0输入,反馈速度为fast,输出为A1,A3或者A5
  OA0CTL1=OAFBR_1+OAFC_2;                 //R2/R1=4R/16R,反馈电阻为4R
  //OA0CTL1=OAFBR_2+OAFC_2;               //R2/R1=8R/8R,反馈电阻为8R
  //OA0CTL1=OAFBR_3+OAFC_2;               //R2/R1=10R/6R,反馈电阻为10R
  //OA0CTL1=OAFBR_4+OAFC_2;               //R2/R1=12R/4R,反馈电阻为12R
  //OA0CTL1=OAFBR_5+OAFC_2;               //R2/R1=13R/3R,反馈电阻为13R
  //OA0CTL1=OAFBR_6+OAFC_2;               //R2/R1=14R/2R,反馈电阻为14R
  //OA0CTL1=OAFBR_7+OAFC_2;               //R2/R1=15R/1R,反馈电阻为15R
  _NOP();
  _BIS_SR(LPM3_bits);                     //进入低功耗3   
  _NOP();
  return 0;  
}