main.c

msp430F22x4的C语言程序示例.

#include "msp430x22x4.h"
//OA0工作在模式4(non_inverting)
//p2.0输入(零点几个伏特)
//p2.1输出(最大输出AVCC)
//将输入电压的地接到芯片的AVss
//用万用表来观察在各个放大系数时输出端电压
//                 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_0+OAFC_4;                 //R2/R1=0R/16R,模式4(同向比例放大器,放大系数=1+R2/R1)
  OA0CTL1=OAFBR_1+OAFC_4;                 //R2/R1=4R/12R
  OA0CTL1=OAFBR_2+OAFC_4;                 //R2/R1=8R/8R
  OA0CTL1=OAFBR_3+OAFC_4;                 //R2/R1=10R/6R
  OA0CTL1=OAFBR_4+OAFC_4;                 //R2/R1=12R/4R
  OA0CTL1=OAFBR_5+OAFC_4;                 //R2/R1=13R/3R
  OA0CTL1=OAFBR_6+OAFC_4;                 //R2/R1=14R/2R
  OA0CTL1=OAFBR_7+OAFC_4;                 //R2/R1=15R/1R
  _NOP();
  _BIS_SR(LPM3_bits);                     //进入低功耗3   
  _NOP();
  return 0;  
}