Diff: AntennaLog.cpp

Revision:

3:9b47638100af

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/AntennaLog.cpp	Tue Apr 08 21:01:31 2014 +0000
@@ -0,0 +1,85 @@
+#include "mbed.h"
+#define PI 3.1415
+#include "C12832.h"
+
+LocalFileSystem local("local");               // Create the local filesystem under the name "local"
+
+C12832 lcd(p5, p7, p6, p8, p11);
+
+Timer     t;
+
+AnalogIn   ain_v1(p19); // Input voltage from antenna
+
+    // Global variables declared
+    float v1, m, b, p_in, Pt, Gt, Gr, Pr, f, c, r;
+    float lv_r[250], lv_v1[250];
+    int k;
+
+int main()
+{
+    
+    // Open logging file
+    FILE *fp = fopen("/local/mBedOutp.m", "w"); 
+    
+    //logging setup 
+    for(k=0;k<250;k++)
+     { 
+        lv_r[k]      = 0.0;
+        lv_v1[k]     = 0.0;
+     }
+    k = 0;
+    
+    t.start();
+    while(k<250)
+    {
+    // Voltage to Power calculations
+    v1      = ain_v1*3.33;           // ain_v1;   // Comes from antenna (Can adjust manually for now) (3.3 is for scaling voltage properly... ask Feemster why this is necessary.
+    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      = .0398;            //(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? 7 milliwatt?
+    Pr      = pow(10, ((p_in-30)/10)); // (watts)
+    
+    // Free Space Loss Terms
+    f       = 2400000000;       // (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);
+    
+    printf("\rRange (meters)    = %.3f\n\r",r);
+    //printf("Power (watts)     = %.3f\n\r",Pr);
+    printf("Voltage into mBed = %.4f\n\r",v1);
+    //printf("%.4f\n\r",v1);
+    
+    lcd.cls();
+    lcd.locate(0,3);
+    lcd.printf("Voltage (volts) = %.4f",v1);
+    
+    lcd.locate(0,15);
+    lcd.printf("Range (meters) = %.4f",r);
+    
+      //LOG stuff
+    if(k<250)
+    {   lv_r[k]     = r;
+        lv_v1[k]    = v1;
+        k++;
+    }
+    
+    } // End of while=======================================================
+    
+    if(1)
+    {
+    
+    for(k=0;k<250;k++)
+    {   fprintf(fp,"lv.r(%d,1)  = %.3f;\n",k+1,lv_r[k]);
+        fprintf(fp,"lv.v1(%d,1) = %.4f;\n",k+1,lv_v1[k]);
+    }
+    
+    }// End of IF loop
+    
+    fclose(fp);
+} // End of main loop=======================================================
\ No newline at end of file