单片机FFT音乐频谱分析源代码解析

//电脑音量推荐设置为40%，手机及MP4等要高一些.晶振：32M
#include <STC12C5A60S2.h>
#include<intrins.h>
#define SAMPLE_NUM 128
#define LOG 6
#define TIME 2048    //中断
#define FFT_OUT_MIN 0
#define FFT_OUT_MAX 7
#define OFF L1=L2=L3=L4=L5=L6=L7=L8=L9=L10=L11=L12=L13=L14=L15=L16=L17=L18=L19=L20=L21=L22=L23=L24=1;
#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_SPEEDH  0x40            //140 clocks  
//采样存储序列表
unsigned char code BRTable[SAMPLE_NUM] ={
0, 64, 32, 96, 16, 80, 48, 112,
8, 72, 40, 104, 24, 88, 56, 120,
4, 68, 36, 100, 20, 84, 52, 116,
12, 76, 44, 108, 28, 92, 60, 124,
2, 66, 34, 98, 18, 82, 50, 114,
10, 74, 42, 106, 26, 90, 58, 122,
6, 70, 38, 102, 22, 86, 54, 118,
14, 78, 46, 110, 30, 94, 62, 126,
1, 65, 33, 97, 17, 81, 49, 113,
9, 73, 41, 105, 25, 89, 57, 121,
5, 69, 37, 101, 21, 85, 53, 117,
13, 77, 45, 109, 29, 93, 61, 125,
3, 67, 35, 99, 19, 83, 51, 115,
11, 75, 43, 107, 27, 91, 59, 123,
7, 71, 39, 103, 23, 87, 55, 119,

15, 79, 47, 111, 31, 95, 63, 127};
char code sin_tabb[SAMPLE_NUM] = {0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 59, 65, 70, 75, 80, 85, 89, 94, 98, 102, 
105, 108, 112, 114, 117, 119, 121, 123, 124, 125, 126, 126, 126, 126, 126, 125, 124, 123, 121, 119, 117, 114, 112, 
108, 105, 102, 98, 94, 89, 85, 80, 75, 70, 65, 59, 54, 48, 42, 36, 30, 24, 18, 12, 6, 0, -6, -12, -18, -24, -30, 
-36, -42, -48, -54, -59, -65, -70, -75, -80, -85, -89, -94, -98, -102, -105, -108, -112, -114, -117, -119, -121, 
-123, -124, -125, -126, -126, -126, -126, -126, -125, -124, -123, -121, -119, -117, -114, -112, -108, -105, -102, 
-98, -94, -89, -85, -80, -75, -70, -65, -59, -54, -48, -42, -36, -30, -24, -18, -12, -6};                         
char code cos_tabb[SAMPLE_NUM] = {127, 126, 126, 125, 124, 123, 121, 119, 117, 114, 112, 108, 105, 102, 98, 94, 
89, 85, 80, 75, 70, 65, 59, 54, 48, 42, 36, 30, 24, 18, 12, 6, 0, -6, -12, -18, -24, -30, -36, -42, -48, -54, -59, 
-65, -70, -75, -80, -85, -89, -94, -98, -102, -105, -108, -112, -114, -117, -119, -121, -123, -124, -125, -126, -
126, -126, -126, -126, -125, -124, -123, -121, -119, -117, -114, -112, -108, -105, -102, -98, -94, -89, -85, -80, 
-75, -70, -65, -59, -54, -48, -42, -36, -30, -24, -18, -12, -6, 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 59, 65, 70, 
75, 80, 85, 89, 94, 98, 102, 105, 108, 112, 114, 117, 119, 121, 123, 124, 125, 126, 126};
xdata unsigned char result[128];
xdata unsigned char temp[128];
xdata unsigned char num[128];
unsigned char anum,timernum,timernum2,lednum3,Ltime,t;//用于分离
unsigned char lednum[]={0x01,0x03,0x07,0x0f,0x1f,0x3f,0x7f,0xff};//0-7的显示数组  P2组控制
int xdata FftReal[SAMPLE_NUM];
int xdata FftImage[SAMPLE_NUM];
unsigned char code musicdisplay[]={
0x00,0x00,
0xFE,0x40,0x30,0x40,0xFE,0x00, // -M-
0xFC,0x02,0x02,0x02,0xFC,0x00, // -U-
0x64,0x92,0x92,0x92,0x4C,0x00, // -S-
0x00,0x82,0xFE,0x82,0x00,0x00, // -I-
0x7C,0x82,0x82,0x82,0x44,0x00, // -C-
0x00,0x00,0x00,
0xFE,0x82,0x82,0x82,0x7C,0x00, // -D-
0x00,0x82,0xFE,0x82,0x00,0x00, // -I-