MSP430单片机实现FFT(全国大学生电子设计大赛获奖作品)

#include "MSP430X16X.h" #include "math.h" #include "OCMJ4X8C.h" #include"MSP430KEY.h" #include"df_timera.h" #define num_point 256 //取样点数 #define num_grade 8 //蝶形运算阶数 const float tab_sin[256]={ 0, 0.0245, 0.0491, 0.0736, 0.0980, 0.1224, 0.1467, 0.1710, 0.1951, 0.2191, 0.2430, 0.2667, 0.2903, 0.3137, 0.3369, 0.3599, 0.3827, 0.4052, 0.4276, 0.4496, 0.4714, 0.4929, 0.5141, 0.5350, 0.5556, 0.5758, 0.5957, 0.6152, 0.6344, 0.6532, 0.6716, 0.6895, 0.7071, 0.7242, 0.7410, 0.7572, 0.7730, 0.7883, 0.8032, 0.8176, 0.8315, 0.8449, 0.8577, 0.8701, 0.8819, 0.8932, 0.9040, 0.9142, 0.9239, 0.9330, 0.9415, 0.9495, 0.9569, 0.9638, 0.9700, 0.9757, 0.9808, 0.9853, 0.9892, 0.9925, 0.9952, 0.9973, 0.9988, 0.9997, 1.0000, 0.9997, 0.9988, 0.9973, 0.9952, 0.9925, 0.9892, 0.9853, 0.9808, 0.9757, 0.9700, 0.9638, 0.9569, 0.9495, 0.9415, 0.9330, 0.9239, 0.9142, 0.9040, 0.8932, 0.8819, 0.8701, 0.8577, 0.8449, 0.8315, 0.8176, 0.8032, 0.7883, 0.7730, 0.7572, 0.7410, 0.7242, 0.7071, 0.6895, 0.6716, 0.6532, 0.6344, 0.6152, 0.5957, 0.5758, 0.5556, 0.5350, 0.5141, 0.4929, 0.4714, 0.4496, 0.4276, 0.4052, 0.3827, 0.3599, 0.3369, 0.3137, 0.2903, 0.2667, 0.2430, 0.2191, 0.1951, 0.1710, 0.1467, 0.1224, 0.0980, 0.0736, 0.0491, 0.0245, 0.0000,-0.0245,-0.0491,-0.0736,-0.0980,-0.1224,-0.1467, -0.1710,-0.1951,-0.2191,-0.2430,-0.2667,-0.2903,-0.3137,-0.3369,-0.3599, -0.3827,-0.4052,-0.4276,-0.4496,-0.4714,-0.4929,-0.5141,-0.5350,-0.5556, -0.5758,-0.5957,-0.6152,-0.6344,-0.6532,-0.6716,-0.6895,-0.7071,-0.7242, -0.7410,-0.7572,-0.7730,-0.7883,-0.8032,-0.8176,-0.8315,-0.8449,-0.8577, -0.8701,-0.8819,-0.8932,-0.9040,-0.9142,-0.9239,-0.9330,-0.9415,-0.9495, -0.9569,-0.9638,-0.9700,-0.9757,-0.9808,-0.9853,-0.9892,-0.9925,-0.9952, -0.9973,-0.9988,-0.9997,-1.0000,-0.9997,-0.9988,-0.9973,-0.9952,-0.9925, -0.9892,-0.9853,-0.9808,-0.9757,-0.9700,-0.9638,-0.9569,-0.9495,-0.9415, -0.9330,-0.9239,-0.9142,-0.9040,-0.8932,-0.8819,-0.8701,-0.8577,-0.8449, -0.8315,-0.8176,-0.8032,-0.7883,-0.7730,-0.7572,-0.7410,-0.7242,-0.7071, -0.6895,-0.6716,-0.6532,-0.6344,-0.6152,-0.5957,-0.5758,-0.5556,-0.5350, -0.5141,-0.4929,-0.4714,-0.4496,-0.4276,-0.4052,-0.3827,-0.3599,-0.3369, -0.3137,-0.2903,-0.2667,-0.2430,-0.2191,-0.1951,-0.1710,-0.1467,-0.1224, -0.0980,-0.0736,-0.0491,-0.0245}; //float tab_dftR[num_point]; //输入的波形数据，兼作输出数据的实部 float tab_dftI[num_point]; //输出数据的虚部 float tab_power[num_point]; //模，频率对应的功率谱 float result[num_point]; //AD转换结果 float power_t=0; //时域总功率 float power_f=0; //频域总功率 unsigned int data1; unsigned int data2; unsigned char disp1[16]; unsigned char disp2[16]; unsigned int num_B=0; unsigned int mem[num_point]; //以下为液晶显示信息 unsigned char Text[]= { "中山大学 " "请按E 键开始 " "音频信号分析仪 " "按R 键返回 " }; unsigned char Start[]= { "按E 键采集信号 " "按R 键返回 " "进行FFT 分析 " "系统会在5S后返回" }; unsigned char Sure[]= { "请按确定键把FFT " "每按一次显示 " "的功率谱分布显示" "一个功率值 " }; void InitSys(); void fft(float dataR[num_point],float dataI[num_point]); //FFT变换 void get_power_t(float result[num_point]);//计算时域功率,一定要放于void FFT前,否则result数据被覆盖 void get_power(float result[num_point],float dataI[num_point]); //求模 void AD_timeB(); void AdcConvert(unsigned char *Numeral,unsigned int result); void sort(float* mod,unsigned int* count_in);//排序 //static unsigned int length; void main( void ) { unsigned char key[2],LCD_data[16]; unsigned int count,freq_count; unsigned long data1,data2; float data3,data4; signed long Chan_data; unsigned int count_index[num_point/2]; WDTCTL = WDTPW + WDTHOLD; //关闭看门狗 for(unsigned int p0=0;p0<num_point/2;p0++) count_index[p0]=p0; InitSys(); start: count=0; chn_disp (Text);//输出实验人信息 while(1) { key[0]=GetKeyZhi(&key[1]); if(key[0]==0x84) break; LPM3; } clrram(); chn_disp(Start); /* while(1) { key[0]=GetKeyZhi(&key[1]); if(key[0]==0x88) goto start; if(key[0]==0x84) break; LPM3; } clrram(); chn_disp(Signal); */ AD_timeB(); while(1) { if(num_B==num_point) { ADC12CTL0&=~ENC; TBCTL&=~(BIT5+BIT4); break; } } for(unsigned int q4=0;q4<num_point;q4++) { Chan_data=mem[q4]; Chan_data -=0x7FF; Chan_data *=5; result[q4] =((float)Chan_data)/4095; } get_power_t(result); fft(result,tab_dftI); get_power(result,tab_dftI); sort(tab_power,count_index); clrram(); chn_disp(Sure); while(1) { key[0]=GetKeyZhi(&key[1]); if(key[0]==0x88) goto start; if(key[0]==0x84) break; } /* freq_count =count_index[count]*100; data3=tab_power[count]; data1=(unsigned int)tab_power[count]; tab_power[count]=tab_power[count]-data1; data2=(unsigned int)(tab_power[count]*10000); tab_power[count]=data3; Convert(LCD_data,data1,data2,freq_count); line_disp(LCD_data,0x80); count++; */ freq_count =count_index[count]*100; data3=tab_power[count]; data1=(unsigned int)data3; data3=data3-data1; data2=(unsigned int)(data3*10000); Convert(LCD_data,data1,data2,freq_count); line_disp(LCD_data,0x80); count++; freq_count =count_index[count]*100; data3=tab_power[count]; data1=(unsigned int)data3; data3=data3-data1; data2=(unsigned int)(data3*10000); Convert(LCD_data,data1,data2,freq_count); line_disp(LCD_data,0x90); count++; freq_count =count_index[count]*100; data3=tab_power[count]; data1=(unsigned int)data3; data3=data3-data1; data2=(unsigned int)(data3*10000); Convert(LCD_data,data1,data2,freq_count); line_disp(LCD_data,0x88); count++; freq_count =count_index[count]*100; data3=tab_power[count]; data1=(unsigned int)data3; data3=data3-data1; data2=(unsigned int)(data3*10000); Convert(LCD_data,data1,data2,freq_count); line_disp(LCD_data,0x98); while(1); /* while(count!=101) { key[0]=GetKeyZhi(&key[1]); if(key[0]==0x88) goto start; if(key[0]==0x84) { clrram(); tab_power[count]*=10000; data1=(unsigned int)tab_power[count]; freq_count =count*100; count++; Convert(LCD_data,data1,freq_count); line_disp(LCD_data,0x80); tab_power[count]*=10000; data2=(unsigned int)tab_power[count]; freq_count =count*100; count++; Convert(LCD_data,data2,freq_count); line_disp(LCD_data,0x90); tab_power[count]*=10000; data3=(unsigned int)tab_power[count]; freq_count =count*100; count++; Convert(LCD_data,data3,freq_count); line_disp(LCD_data,0x88);