PIC16F877A的50HZ正弦波

只看该作者 · 2019-11-8 14:37

#include <pic.h>//包含单片机内部资源预定义

#include <math.h>



unsigned char const sin_32[]={104,109,114,119,124,128,133,137,142,146,150,154,157,161,164,//15

167,169,172,174,176,177,178,179,180,180,180,180,179,178,176,175,173,171,168,165,//20

162,159,156,152,148,144,140,135,131,126,121,116,111,106,101,96,91,86,81,76,72,67,63,//23

58,54,50,46,43,39,36,33,31,28,26,24,23,22,21,20,20,20,20,21,22,24,25,27,29,32,35,38,//42

41,44,48,52,56,60,65,69,74,79,84,89,94,99

};//浮点型精度高，换其他会出现尖角



void work0();

unsigned char set_pwm;

void main(void)

{    

    work0();

    while(1)

    {

    }

}



void work0()//m=0.8;T=(PR2+1)*4*f*TIMR2分频

{

    //CCPR1L=0X00;//设置CCP1,0%的脉宽输出

    TRISC=0X00;//PORTC are outputs

    CCP1CON=0x0C;//0000 1100，设置CCP1为PWM工作方式，且工作循环位的低两位为00

    PR2=199;//设置PWM周期:(PR2+1)*4*Tosc*(TMR2预分频数1)=200u(5k)

    T2CON=0x04;//Tc赋值=T*D=(PR2+1)*D=200*D

    CCP1IE=1;

    INTCON=0xC0;//GIE=1,开总中断，开启第一外设中断外围功能模块中断

    TMR2IE=1;TMR2IF=0;

}



//interrupt//

void interrupt pic(void)

{

    if(TMR2IF&TMR2IE)

    {  

        set_pwm++;

        TMR2IF=0;CCP1IF=0;

        CCPR1L=sin_32[set_pwm];

        if(set_pwm==99) set_pwm=0;

    }

}

1万 · 2019-11-8 17:25

这种查表操作。