Diff: cal.cpp

Revision:

0:1b13f03ce7eb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cal.cpp	Thu Mar 08 14:38:32 2018 +0000
@@ -0,0 +1,93 @@
+#include "mbed.h"
+#include "math.h"
+#include "cal.h"
+
+//calcualte |Zx|,Cx, Rx
+void cal_Zx (
+    double z, double a,double f,int type, //input 
+    double Ro,//constant
+    double *ZxMag, double *Cx, double *Rx//output
+    )
+{   //unit&description: 
+    //  z       ohm, magnitude of impedance of Zx+Ro
+    //  a       degree, angle of Zx+Ro. angle is measured at 10kHz
+    //  f       Hz, the frequency when measure z and a 
+    //  type    1-series or 2-parallel
+    //  Ro      ohm, split resistor 33ohm typically
+    //  *ZxMag  ohm, magnitude of DUT
+    //  *Cx     F, cap of DUT
+    //  *Rx     ohm, resistance of DUT 
+    double w=2*M_PI*f;
+    double arad=a/180*M_PI;
+    
+    double Rx2=0,Cx2=0;
+    double Zx=0;
+    
+    double Re=0,Im=0;
+    double arad2=0;
+    double temp;
+    if (type!=1&&type!=2)
+        printf("wrong type");
+    else if(type==1){//series
+        Rx2=z*cos(arad)-Ro;
+        Cx2=1/(z*sin(arad)*w);
+        Zx=sqrt(Rx2*Rx2+(z*sin(arad))*(z*sin(arad)));
+        }
+    else{//if type==2 parallel
+        Re=z*cos(arad)-Ro;//real part of Zx parallel
+        Im=z*sin(arad);
+        Zx=sqrt(Re*Re+Im*Im);
+        arad2=atan2(Im,Re);
+        Rx2=Zx/cos(arad2);
+        Cx2=sin(arad2)/(Zx*w);
+        }
+   *ZxMag=Zx;
+   *Cx=Cx2;
+   *Rx=Rx2;
+}
+    
+double cal_z(double Vin,double Vo,double Rs)
+{
+    return Vin/Vo*Rs;
+    
+}
+
+
+double pwToAngle(int pw)
+{   //angle,pw is measured at 10kHz
+    //10kHz=100us=1e-4s
+    //unit  pw: number of counts, 50us=320counts
+    //      angle degree
+    //pw id pulse width of level 0
+    double angle=1;
+    double temp=0;
+    if (pw>=320||pw<=480)
+    {   
+        //angle=(pw-320)/320*180;
+        temp=(double)pw;//+0.5
+        angle=temp/16*9-180;
+        return angle;
+        }
+    else if (pw>=160||pw<=320)
+    {
+        //angle=(320-pw)/320*180;
+        temp=(double)pw;//+0.5
+        angle=180-temp/16*9;
+        return angle;
+        }
+    else //if the pw is in the above range
+        {//the result angle must be in 0~90
+            printf ("wrong pw");
+            return 0;
+        }
+}
+
+int check_angle(double angle)
+{   //absolute angle must be within (0,90)
+    //the excat angle of RC is (-90,0)
+    //0 wrong angle, 1 correct
+    if (angle>90 || angle <0)
+            return 0;
+    else 
+            return 1;   
+}