Diff: main.cpp

Revision:

2:d5b23f4e6884

Parent:

1:2178a66e1223

diff -r 2178a66e1223 -r d5b23f4e6884 main.cpp
--- a/main.cpp	Fri Mar 28 01:42:38 2014 +0000
+++ b/main.cpp	Wed Apr 02 12:26:31 2014 +0000
@@ -1,35 +1,40 @@
 #include "mbed.h"
-#define PI 3.1415926
+#define PI 3.1415
 
-AnalogIn   ain_v1(p20); // 
-//AnalogIn   ain_v2(p19);
+Timer     t;
+
+AnalogIn   ain_v1(p20); // Input voltage from antenna
+
 
 int main()
 {
-    float v1, m, b, p_in, c, r, f
-    int value1
+    float v1, m, b, p_in, Pt, Gt, Gr, Pr, f, c, r;
     
+    t.start();
+    while(t.read()<10.0)
+    {
     // Voltage to Power calculations
-    v1      = ain_v1;   // Comes from mBed (Can adjust manually for now)
-    b       = 2.095;    // (volts) Direct function generator measurement
-    m       = .0316;    // volts/dBm (Calculated at 2000 MHz and 0 and -40 dBm)
-    p_in    = (v1-b)/m; // Derived from v = m*p+b (linear relationship of voltage and power)
-                    // m = slope , v1 = vin, b = y-intercept
+    v1      = ain_v1;           // ain_v1;   // Comes from mBed (Can adjust manually for now)
+    b       = 2.095;            // (volts) Direct function generator measurement
+    m       = .0316;            // volts/dBm (Calculated at 2000 MHz and 0 and -40 dBm)
+    p_in    = (v1-b)/m;         // Derived from v = m*p+b (linear relationship of voltage and power)
    
     // Range equation Terms
-    Pt      = .001;  //(mW or 0 dBm) Power Transmitted. This should be constant for a phone I think... it just changes with the function generator
-    Gt      = 1;     // Unitless (1 for FG)
-    Gr      = ??;    // How do we get this? Should be on datasheet... but calc required? 
-    Pr      = p_in;
+    Pt      = .001;             //(watts or 1mW or 0 dBm) Power Transmitted. This is ~16 dBm (.0398 watts) for an iphone 5
+    Gt      = 1;                // Unitless (1 for FG)                      Shouldn't both of these gains be 'directive' gains, not power gains
+    Gr      = .007;                // (.007) (7 mW) How do we get this? Should be on datasheet... but calc required? 7 milliwatt?
+    Pr      = pow(10, ((p_in-30)/10)); // (watts)
     
     // Free Space Loss Terms
-    f       = 2000    // (MHz) This will be constant for a phone... but what to put for the FG
-    c       = 2.99792458*10^8;
+    f       = 2000000000;       // (Hz) This will be constant for a phone... but what to put for the FG
+    c       = 300000000;        // m/s
+    
+    r       = (c*(sqrt(Pt*Gt*Gr)/Pr))/(4*PI*f);
     
-    r       = [c*(sqrt(Pt*Gt*Gr)/Pr)]/(4*PI*f);
-    
-    
-    
+    //printf("\rRange  (meters) = %.3f\n\r",r);
+    //printf("Power    (watts) = %.4f\n\r",Pr);
+    printf("Voltage into mBed = %.4f\n\r",v1);
+    }
 }