ppy.rar_12864 频谱_51 fft_FFT频谱显示_fft_fft 51

/*------------------------------------------------------------------------------------*/ /* --- STC MCU International Limited ---------------------------------------*/ /* --- 演示STC 1T 系列单片机??A/D转换功能-----------------------------*/ /* --- Mobile: (86)13922805190 -----------------------------------------------*/ /* --- Fax: 86-755-82944243 ---------------------------------------------------*/ /* --- Tel: 86-755-82948412 ----------------------------------------------------*/ /* --- Web: www.STCMCU.com -----------------------------------------------*/ /* 如果要在程序中使用或在文章中引用该程序， -------------------- ---*/ /* 请在程序中或文章中注明使用了宏晶科技的资料及程序 -----------*/ /*-------------------------------------------------------------------------------------*/ //#include "stdafx.h" #include "stdio.h" #include "math.h" #include "stdlib.h" //#include "graphics.h" //#include "conio.h" /*定义复数类型*/ typedef struct { double real; double img; }complex; #include "reg51.h" #include "intrins.h" #define FOSC 18432000L #define BAUD 9600 typedef unsigned char BYTE; typedef unsigned int WORD; /*Declare SFR associated with the ADC */ //锁定地址 sfr ADC_CONTR = 0xBC; //ADC control register sfr ADC_RES = 0xBD; //ADC hight 8-bit result register sfr ADC_RESL = 0xBE; //ADC low 2-bit result register sfr P1ASF = 0x9D; //P1 secondary function control register /*Define ADC operation const for ADC_CONTR*/ //设定参数 #define ADC_POWER 0x80 //ADC power control bit #define ADC_FLAG 0x10 //ADC complete flag #define ADC_START 0x08 //ADC start control bit #define ADC_SPEEDLL 0x00 //540 clocks #define ADC_SPEEDL 0x20 //360 clocks #define ADC_SPEEDH 0x40 //180 clocks #define ADC_SPEEDHH 0x60 //90 clocks #define N 8 #define uint unsigned int #define uchar unsigned char #define LcdBus P2 //#define columnBase 0x40/*列基址：列地址是横向的，从0-127，共128列 */ //#define pageBase 0xB8/*页基址：页是纵向的，每个汉字分两页，每页16行8列点。*/ /*锁定管脚*/ sbit CS1 = P3^3; sbit CS2 = P3^4; sbit EP = P3^0; sbit RS = P3^2; sbit RW = P3^1; sbit RST = P3^5; //#include<reg51.h> double Fn=0,An=0,Qn=0; BYTE Fn_char[8], An_char[8],Qn_char[8]; /*函数声明*/ void InitUart(); void SendData(BYTE dat); void delay(WORD n); //void adc_isr(); interrupt 5 using 1 void InitADC(); void fft(); /*快速傅里叶变换*/ void initW(); /*初始化旋转因子*/ void change(); /*变址*/ void add(complex ,complex ,complex *); /*复数加法*/ void mul(complex ,complex ,complex *); /*复数乘法*/ void sub(complex ,complex ,complex *); /*复数减法*/ void divi(complex ,complex ,complex *); /*复数除法*/ void output(); void yunsuan(void); void delay_50ms(WORD n); void delay_50us(uint i); complex x[N]; /*输入序列,旋转因子*/ complex *W; int FS= 1852; //采样频率，跟采样速度有关 double PI; BYTE ch = 0; //ADC channel NO. int adc_count=0; //adc转换次数统计 void mainadc() { InitUart(); //Init UART, use to show ADC result InitADC(); //Init ADC sfr IE = 0xa0; //Enable ADC interrupt and Open master interrupt switch //adc_isr(); //Start A/D conversion } /*----------------------------ADC interrupt service routine----------------------------*/ void adc_isr() interrupt 5 using 1 //使用5中断，第一工作区 { double AD_val; ADC_CONTR &= !ADC_FLAG; //Clear ADC interrupt flag AD_val= ((ADC_RES*4+ADC_RESL)*5)/1024; x[adc_count++].real=AD_val; x[adc_count].img=0; //SendData(ch); //Show Channel NO. //SendData(ADC_RES); //Get ADC high 8-bit result and Send to UART //if you want show 10-bit result, uncomment next line //SendData(ADC_LOW2); //Show ADC low 2-bit result //if (++ch > 7) ch = 0; //switch to next channel ADC_CONTR = ADC_POWER | ADC_SPEEDLL | ADC_START | ch; if (adc_count>=N) return; } /*----------------------------Initial ADC sfr----------------------------*/ void InitADC( ) { P1ASF = 0x01; //Set all P1 as analog input port ADC_RES = 0; //Clear previous result ADC_RESL= 0; ADC_CONTR = ADC_POWER | ADC_SPEEDLL | ADC_START | ch; delay_50us(2); //ADC power-on delay and Start A/D conversion } /*----------------------------Initial UART----------------------------*/ /*void InitUart() { SCON = 0x5a; //8 bit data ,no parity bit TMOD = 0x20; //T1 as 8-bit auto reload TH1 = TL1 = -(FOSC/12/32/BAUD); //Set Uart baudrate TR1 = 1; //T1 start running }*/ /*----------------------------Send one byte data to PCInput: dat (UART data)Output:-----------------------------*/ /*void SendData(BYTE dat) { while (!TI); //Wait for the previous data is sent TI = 0; //Clear TI flag SBUF = dat; //Send current data }*/ /*----------------------------Software delay function----------------------------*/ void delay_50ms(WORD n) { WORD x; while (n--) { x = 6245; while (x--); } } /******************************************************************** 正弦函数快速傅立叶变换C程序 函数简介： 输入正弦函数的频率FC，然后由采样定理进行采样，采样频率为FS，采样后进行M点快速傅立叶变换，最后输出结果并画图。 使用说明：FS>=2FC，M为2的整数次幂。 ********************************************************************/ int mainfft() { //int i; PI=atan(1)*4; /*int gd=DETECT,gm; system("cls"); printf("输入正弦频率FC:\n"); scanf("%d",&FC); printf("输入采样频率FS(FS>=FC):\n"); scanf("%d",&FS); printf("输入采样点数M(2的整数次幂):\n"); scanf("%d",&M); for(i=0;i<M;i++) { x[i].real=sin(2*PI*FC*i/FS); x[i].img=0; } */ initW(); fft(); yunsuan(); /*output(); for(i=0;i<N;i++) { x[i].real=sqrt(x[i].real*x[i].real+x[i].img*x[i].img); }*/ /*initgraph(&gd,&gm,""); cleardevice(); setcolor(GREEN); line(300,400,300,50); line(300,50,295,55); line(300,50,305,55); line(40,400,600,400); line(600,400,595,395); line(600,400,595,405); setcolor(WHITE); for(i=0;i<M;i++) line(i*5+300-M*5/2,400,i*5+300-M*5/2,400-(int)x[i].real*5); getch(); closegraph();*/ return 0; } void yunsuan(void) { int i=0,max=0; double fn=0,an=0,qn=0,temp; for(i=0;i<=N;i++) { temp=sqrt(x[i].real*x[i].real+x[i].img*x[i].img); if(temp>=an) { an=temp; max=i; } } An=an/(N/2); Fn=(max-1)*FS/N; Qn=180*atan(x[max].img/x[max].real)/PI; sprintf(An_char,"%8.2f",An); sprintf(Fn_char,"%8.2f",Fn); sprintf(Qn_char,"%8.2f",Qn); } /*快速傅里叶变换*/ void fft() { int i=0,j=0,k=0,l=0; complex up,down,product; change(); for(i=0;i< log(N)/log(2) ;i++) { l=1<<i; for(j=0;j<N;j+= 2*l ) { for(k=0;k<l;k++) { mul(x[j+k+l],W[N*k/2/l],&product); add(x[j+k],product,&up); sub(x[j+k],product,&down); x[j+k]=up; x[j+k+l]=down; } } } } /*初始化旋转因子*/ void initW() { int i; W=(complex *)malloc(sizeof(complex) * N); for(i=0;i<N;i++) {