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// Target : M32 // Crystal: 4.0000Mhz #include <iom32.h> #include <ina90.h> #include "delay.h" //#include <ioavr.h> // Use IAR-AVR library #define uchar unsigned char #define uint unsigned int #define N 98 // 正弦波样本表 __flash unsigned char auc_sinparam[N] = { 128,136,144,152,160,168,175,183,190,197,204,210,216,222,227,232, 237,241,244,247,250,252,253,254,255,255,254,253,252,250,247,244, 241,237,232,227,222,216,210,204,197,190,183,175,168,160,152,144, 136,128,119,111,103,95,87,80,72,65,58,51,45,39,33,28, 23,18,14,11,8,5,3,2,1,0,0,1,2,3,5,8, 11,14,18,23,28,33,39,45,51,58,65,72,80,87,95,103, 111,119 }; unsigned int x_sw=1; unsigned int indexU=0; unsigned int indexV=N/3; unsigned int indexW=2*N/3; //timer0溢出中断 #pragma vector=TIMER0_OVF_vect __interrupt void timer0_ovf_isr(void) { indexU+=x_sw; if(indexU>(N-1)) indexU-=N; OCR0 = auc_sinparam[indexU]; indexV+=x_sw; if(indexV>(N-1)) indexV-=N; OCR1A = auc_sinparam[indexV]; indexW+=x_sw; if(indexW>(N-1)) indexW-=N; OCR1B = auc_sinparam[indexW]; } void system_init (void) { //port init PORTB=0xf7; DDRB=0xff; //PB3--OC0 PORTD=0xff;//pd0-pd3 pull-up enable for key1-key4 DDRD=0x30;//PD4--OC1A,PD5--0C1B //timer0 init TCCR0=0x00; OCR0=0xff; //初始值占空比为0 TCCR0=0x62;//相位修正 8分频 正向输出 启动定时器 //time1 init TCCR1A= 0x00; OCR1A = 0xff;//正向输出 OCR1B = 0xff;//正向输出 //ICR1 = 0xff; TCCR1A= 0xa1; TCCR1B= 0x02;//相位修正 8分频 启动定时器 indexU=0; indexV=N/3; indexW=2*N/3; TIMSK=0x01;//time0 over interrupt __enable_interrupt(); //re-enable interrupts } void main(void) { uchar tem,key; system_init();//系统初始化 while(1) { tem=0x0f&PIND; //读取端口b if(tem!=0x0f) //判断是否有按键按下 { //s_ms(50); //排除按键抖动和抗干扰 delay_nms(35); key=0x0f&PIND; if(key==tem) { x_sw++; if(x_sw==6) x_sw=1; if(x_sw==1) //fsin=10hz { PORTB=(1<<PB6)|(1<<PB5)|(1<<PB4)|(1<<PB2)|(1<<PB1)|(1<<PB0); PORTB&=~(1<<PB7); } if(x_sw==2)//fsin=20hz { PORTB=(1<<PB7)|(1<<PB5)|(1<<PB4)|(1<<PB2)|(1<<PB1)|(1<<PB0); PORTB&=~(1<<PB6); } if(x_sw==3)//fsin=30hz { PORTB=(1<<PB7)|(1<<PB6)|(1<<PB4)|(1<<PB2)|(1<<PB1)|(1<<PB0); PORTB&=~(1<<PB5); } if(x_sw==4)//fsin=40hz { PORTB=(1<<PB7)|(1<<PB6)|(1<<PB5)|(1<<PB2)|(1<<PB1)|(1<<PB0); PORTB&=~(1<<PB4); } if(x_sw==5)//fsin=50hz { PORTB=(1<<PB7)|(1<<PB6)|(1<<PB5)|(1<<PB4)|(1<<PB1)|(1<<PB0); PORTB&=~(1<<PB2); } //PORTB=0x0f|(key<<4); //端口D输出按键值 } } //speed_switch();//按键调速 } } 上面的程序有两个错误：、 1、用示波器看到的正弦波频率不是20hz,40hz,60hz,80hz,100hz,而是10hz,20hz,30hz,40hz,50hz,请问是为什么 2、用示波器观察发现：随正弦波频率增大，正弦波幅值会越来越小，请问是为什么 |
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