#include <msp430.h> #include <stdint.h> #include<stdio.h> #include<math.h> #define PI 3.1415926535897932384626433832795028841971 //定义圆周率值 #define FFT_N 128 //定义福利叶变换的点数 struct compx {float real,imag;}; //定义一个复数结构 struct compx s[FFT_N]; //FFT输入和输出:从S[1]开始存放,根据大小自己定义 int i=0; float adcresult; unsigned int *point_1=NULL; unsigned int DMA_DST[16]; // ADC conversion result is stored in this variable void adcdma() { P1OUT &= ~BIT0; // P1.0 clear P1DIR |= BIT0; // P1.0 output P5SEL |= BIT7; // P5.7/TB1 option select P5DIR |= BIT7; // Output direction P6SEL |= BIT0; // Enable A/D channel A0 //Setup Timer B0 TBCCR0 = 0xFFFE; TBCCR1 = 0x8000; TBCCTL1 = OUTMOD_3; // CCR1 set/reset mode TBCTL = TBSSEL_2+MC_1+TBCLR; // SMCLK, Up-Mode // Setup ADC12 ADC12CTL0 = ADC12SHT0_0+ADC12MSC+ADC12ON;// Sampling time, MSC, ADC12 on ADC12CTL1 = ADC12SHS_3+ADC12CONSEQ_2; // Use sampling timer; ADC12MEM0 // Sample-and-hold source = CCI0B = // TBCCR1 output // Repeated-single-channel ADC12MCTL0 = ADC12SREF_0+ADC12INCH_0; // V+=AVcc V-=AVss, A0 channel ADC12CTL0 |= ADC12ENC; // Setup DMA0 DMACTL0 = DMA0TSEL_24; // ADC12IFGx triggered DMACTL4 = DMARMWDIS; // Read-modify-write disable DMA0CTL &= ~DMAIFG; DMA0CTL = DMADT_4+DMAEN+DMADSTINCR_3+DMAIE; // Rpt single tranfer, unchanged dst, Int DMA0SZ = 16; // DMA0 size = 16 __data20_write_long((uintptr_t) &DMA0SA,(uintptr_t) &ADC12MEM0); // Source block address __data20_write_long((uintptr_t) &DMA0DA,(uintptr_t) &DMA_DST); } /******************************************************************* 函数原型:struct compx EE(struct compx b1,struct compx b2) 函数功能:对两个复数进行乘法运算 输入参数:两个以联合体定义的复数a,b 输出参数:a和b的乘积,以联合体的形式输出 *******************************************************************/ struct compx EE(struct compx a,struct compx b) { struct compx c; c.real=a.real*b.real-a.imag*b.imag; c.imag=a.real*b.imag+a.imag*b.real; return(c); } /***************************************************************** 函数原型:void FFT(struct compx *xin,int N) 函数功能:对输入的复数组进行快速傅里叶变换(FFT) 输入参数:*xin复数结构体组的首地址指针,struct型 *****************************************************************/ void FFT(struct compx *xin) { int f,m,nv2,nm1,i,k,l,j=0; struct compx u,w,t; nv2=FFT_N/2; //变址运算,即把自然顺序变成倒位序,采用雷德算法 nm1=FFT_N-1; for(i=0;i<nm1;i++) { if(i<j) //如果i<j,即进行变址 { t=xin[j]; xin[j]=xin[i]; xin[i]=t; } k=nv2; //求j的下一个倒位序 while(k<=j) //如果k<=j,表示j的最高位为1 { j=j-k; //把最高位变成0 k=k/2; //k/2,比较次高位,依次类推,逐个比较,直到某个位为0 } j=j+k; //把0改为1 } { int le,lei,ip; //FFT运算核,使用蝶形运算完成FFT运算 f=FFT_N; for(l=1;(f=f/2)!=1;l++) //计算l的值,即计算蝶形级数 ; for(m=1;m<=l;m++) // 控制蝶形结级数 { //m表示第m级蝶形,l为蝶形级总数l=log(2)N le=2<<(m-1); //le蝶形结距离,即第m级蝶形的蝶形结相距le点 lei=le/2; //同一蝶形结中参加运算的两点的距离 u.real=1.0; //u为蝶形结运算系数,初始值为1 u.imag=0.0; w.real=cos(PI/lei); //w为系数商,即当前系数与前一个系数的商 w.imag=-sin(PI/lei); for(j=0;j<=lei-1;j++) //控制计算不同种蝶形结,即计算系数不同的蝶形结 { for(i=j;i<=FFT_N-1;i=i+le) //控制同一蝶形结运算,即计算系数相同蝶形结 { ip=i+lei; //i,ip分别表示参加蝶形运算的两个节点 t=EE(xin[ip],u); //蝶形运算,详见公式 xin[ip].real=xin[i].real-t.real; xin[ip].imag=xin[i].imag-t.imag; xin[i].real=xin[i].real+t.real; xin[i].imag=xin[i].imag+t.imag; } u=EE(u,w); //改变系数,进行下一个蝶形运算 } } } } int main(void) { WDTCTL = WDTPW+WDTHOLD; // Hold WDT adcdma(); while(!ADC12BUSY==1); point_1=&DMA_DST; adcresult=*point_1/1638.4; for(i=0;i<FFT_N;i++) //给结构体赋值 { //adcresult=DMA_DST/1638.4; //s[i].real=adcresult; s[i].imag=0; //虚部为0 } FFT(s); //进行快速福利叶变换 for(i=0;i<FFT_N;i++) { //求变换后结果的模值,存入复数的实部部分 s[i].real=sqrt(s[i].real*s[i].real+s[i].imag*s[i].imag); } // Destination single address __bis_SR_register(LPM0_bits + GIE); // LPM0 w/ interrupts __no_operation(); // used for debugging } //------------------------------------------------------------------------------ // DMA Interrupt Service Routine //------------------------------------------------------------------------------ #if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__) #pragma vector=DMA_VECTOR __interrupt void DMA_ISR(void) #elif defined(__GNUC__) void __attribute__ ((interrupt(DMA_VECTOR))) DMA_ISR (void) #else #error Compiler not supported! #endif { switch(__even_in_range(DMAIV,16)) { case 0: break; case 2: // DMA0IFG = DMA Channel 0 P1OUT ^= BIT0; // Toggle P1.0 - PLACE BREAKPOINT HERE AND CHECK DMA_DST VARIABLE break; case 4: break; // DMA1IFG = DMA Channel 1 case 6: break; // DMA2IFG = DMA Channel 2 case 8: break; // DMA3IFG = DMA Channel 3 case 10: break; // DMA4IFG = DMA Channel 4 case 12: break; // DMA5IFG = DMA Channel 5 case 14: break; // DMA6IFG = DMA Channel 6 case 16: break; // DMA7IFG = DMA Channel 7 default: break; } }现在DMA的值并取不出来不能赋给一个变量