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_VECTOR
34 __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 = 1us
74 LCD_Set_Pos(1,0);
75 LCD_Show_Deci(hz); //显示
76 flag = 0;
77 }
78 }
79 }
80 #endif
