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Fourier series square wave
main.cpp@0:3052351a8da9, 2017-03-09 (annotated)
- Committer:
- oguro
- Date:
- Thu Mar 09 02:29:54 2017 +0000
- Revision:
- 0:3052351a8da9
Square wave Fourier series;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
oguro | 0:3052351a8da9 | 1 | #include "mbed.h" |
oguro | 0:3052351a8da9 | 2 | #include <math.h> |
oguro | 0:3052351a8da9 | 3 | int i=1,N=50,q=0; |
oguro | 0:3052351a8da9 | 4 | |
oguro | 0:3052351a8da9 | 5 | float wt=0; |
oguro | 0:3052351a8da9 | 6 | |
oguro | 0:3052351a8da9 | 7 | |
oguro | 0:3052351a8da9 | 8 | float aout1=0,aout2=0; |
oguro | 0:3052351a8da9 | 9 | AnalogOut aout(PA_4); |
oguro | 0:3052351a8da9 | 10 | AnalogIn V_adc(PB_1); |
oguro | 0:3052351a8da9 | 11 | float Vr_adc; |
oguro | 0:3052351a8da9 | 12 | Serial pc(USBTX,USBRX); |
oguro | 0:3052351a8da9 | 13 | |
oguro | 0:3052351a8da9 | 14 | DigitalOut myled(LED1); |
oguro | 0:3052351a8da9 | 15 | |
oguro | 0:3052351a8da9 | 16 | Timer timer1; |
oguro | 0:3052351a8da9 | 17 | |
oguro | 0:3052351a8da9 | 18 | |
oguro | 0:3052351a8da9 | 19 | int main(){ |
oguro | 0:3052351a8da9 | 20 | |
oguro | 0:3052351a8da9 | 21 | pc.baud(128000); |
oguro | 0:3052351a8da9 | 22 | const float freq = 10;//50 |
oguro | 0:3052351a8da9 | 23 | |
oguro | 0:3052351a8da9 | 24 | timer1.start(); |
oguro | 0:3052351a8da9 | 25 | |
oguro | 0:3052351a8da9 | 26 | while(1) { |
oguro | 0:3052351a8da9 | 27 | Vr_adc=V_adc.read(); |
oguro | 0:3052351a8da9 | 28 | if(Vr_adc<0.005f){ |
oguro | 0:3052351a8da9 | 29 | N=1; |
oguro | 0:3052351a8da9 | 30 | } |
oguro | 0:3052351a8da9 | 31 | if((Vr_adc>0.005f)&&(Vr_adc<=0.1f)){ |
oguro | 0:3052351a8da9 | 32 | N=2; |
oguro | 0:3052351a8da9 | 33 | } |
oguro | 0:3052351a8da9 | 34 | if((Vr_adc>0.1f)&&(Vr_adc<=0.2f)){ |
oguro | 0:3052351a8da9 | 35 | N=5; |
oguro | 0:3052351a8da9 | 36 | } |
oguro | 0:3052351a8da9 | 37 | if((Vr_adc>0.2f)&&(Vr_adc<=0.4f)){ |
oguro | 0:3052351a8da9 | 38 | N=10; |
oguro | 0:3052351a8da9 | 39 | } |
oguro | 0:3052351a8da9 | 40 | if((Vr_adc>0.4f)&&(Vr_adc<=0.6f)){ |
oguro | 0:3052351a8da9 | 41 | N=20; |
oguro | 0:3052351a8da9 | 42 | } |
oguro | 0:3052351a8da9 | 43 | if((Vr_adc>0.6f)&&(Vr_adc<=0.8f)){ |
oguro | 0:3052351a8da9 | 44 | N=30; |
oguro | 0:3052351a8da9 | 45 | } |
oguro | 0:3052351a8da9 | 46 | if(Vr_adc>0.8f){ |
oguro | 0:3052351a8da9 | 47 | N=60; |
oguro | 0:3052351a8da9 | 48 | } |
oguro | 0:3052351a8da9 | 49 | float s = timer1.read(); |
oguro | 0:3052351a8da9 | 50 | myled = ((int)s) % 2 == 0; /* LED output(0.5Hz) */ |
oguro | 0:3052351a8da9 | 51 | wt=fmodf(s * freq, 1) * 3.14159265359 * 2; |
oguro | 0:3052351a8da9 | 52 | for(i=1;i<=2*N-1;i=i+2){ |
oguro | 0:3052351a8da9 | 53 | //aout2 = VDD/2 +2/VDD* (sin(wt)+sin(3*wt)/3+sin(5*wt)/5+.......) |
oguro | 0:3052351a8da9 | 54 | if(i==0){ |
oguro | 0:3052351a8da9 | 55 | aout1=sin((i-1)*wt)/(i-1); //if i==N i even |
oguro | 0:3052351a8da9 | 56 | } |
oguro | 0:3052351a8da9 | 57 | else{ |
oguro | 0:3052351a8da9 | 58 | aout1=sin(i*wt)/i; |
oguro | 0:3052351a8da9 | 59 | } |
oguro | 0:3052351a8da9 | 60 | aout2=aout2+aout1; |
oguro | 0:3052351a8da9 | 61 | |
oguro | 0:3052351a8da9 | 62 | } |
oguro | 0:3052351a8da9 | 63 | |
oguro | 0:3052351a8da9 | 64 | aout=0.1+(3.3/2+(2*3.3/3.14159265359)*aout2)/5; //VDD=3.3 |
oguro | 0:3052351a8da9 | 65 | aout2=0; |
oguro | 0:3052351a8da9 | 66 | myled = !myled; |
oguro | 0:3052351a8da9 | 67 | if(q>100000){ |
oguro | 0:3052351a8da9 | 68 | timer1.reset(); |
oguro | 0:3052351a8da9 | 69 | q=0; |
oguro | 0:3052351a8da9 | 70 | } |
oguro | 0:3052351a8da9 | 71 | q++; |
oguro | 0:3052351a8da9 | 72 | // if((q%100)==0){ |
oguro | 0:3052351a8da9 | 73 | pc.printf("%.3f \r" ,aout*10); |
oguro | 0:3052351a8da9 | 74 | // } |
oguro | 0:3052351a8da9 | 75 | |
oguro | 0:3052351a8da9 | 76 | } |
oguro | 0:3052351a8da9 | 77 | |
oguro | 0:3052351a8da9 | 78 | |
oguro | 0:3052351a8da9 | 79 | |
oguro | 0:3052351a8da9 | 80 | |
oguro | 0:3052351a8da9 | 81 | } |