1 #include "timerHz.h" 2 #include "msp430g2553.h" 3  4 #define _DEBUG_TIMERHZ_ 5  6 unsigned int capArray[16] = {0}; 7 unsigned char index = 2, flag = 0; 8 float hz = 0; 9 10 /*11  * 绝对值12  */13 int abs(int x)14 {15     return x>0?x:-x;16 }17 18 /*19  * 系统初始化20  */21 void HZ_Init()22 {23     P1SEL |= BIT1;        //P1.1复用24     P1DIR &= ~BIT1;        //P1.1输入25 //    P1SEL |= BIT2;        //P1.2复用26 //    P1DIR &= ~BIT2;        //P1.2输入27 28     CCTL0 = CM_1 + SCS + CCIS_0 + CAP + CCIE;             //上升沿捕获,同步,信号源设置,捕获功能,允许捕获中断29     TACTL = TASSEL_2 + MC_2;                        //定时器的时钟源选择SMCLK(16M)，连续计数30 }31 32 /******************中断服务程序*****************************/33 #pragma vector=TIMER0_A0_VECTOR34 __interrupt void TIME0_A0_ISR(void)35 {36     capArray[index--] = TA0CCR0;37     if(index == 0)38     {39         index = 2;40         TA0CCR0 = 0;        // 清零计数器41         flag = 1;42     }43 }44 45 #ifdef _DEBUG_TIMERHZ_46 #include "12864.h"47 #include "sys.h"48 49 void main()50 {51     double temp = 213.456;52 //    unsigned char i;53 54     System_Init();55     LCD_Init();56     HZ_Init();57 58     LCD_Show_String("Measure freq:");59     LCD_Set_Pos(1,0);60     LCD_Show_Deci(temp);61     LCD_Set_Pos(1,5);62     LCD_Show_String("Hz");63     LCD_Set_Pos(1,0);64 65     _EINT();66     while(1)67     {68         if (flag == 1)69         {70 //            for (i = 0; i<=2; i += 2)71 //                temp += abs(capArray[i+1] - capArray[i]);72             temp = abs(capArray[1] - capArray[2]);73             hz = ((double )(1000000))/temp;            //1MHZ,1/1000000s = 1us74             LCD_Set_Pos(1,0);75             LCD_Show_Deci(hz);        //显示76             flag = 0;77         }78     }79 }80 #endif