Wind vane microcontroller code

Here is the code now used to calculate the measured apparent wind angle in this system.

The analog-to-digital code makes use of the files ‘adc.h’ and ‘adc.c’ found in this BDMICRO sample code. These 2 files shall be included in the project and be part of the compilation.

 

//...

#include "adc.h"

//...

#define PI 3.14159265
#define DEG_TO_RAD ((double)(PI/180.0))
#define RAD_TO_DEG ((double) (180.0/PI))

double awa_measured;

// Wind vane calibration data
double wcx[2];
double wcy[2];
double xc;
double yc;

uint16_t green, blue;

int main(void)
{
   // ...
  
   xc = 741.2638;
   yc = 744.6921;
   wcx[0] = 1.002073;
   wcx[1] = -0.006924865;
   wcy[0] = -0.006924865;
   wcy[1] = 1.023132;
  
   /* initialize A/D Converter */
   adc_init();

  
   for(;;)
   {
      // begin a new cycle

      // ...
 
      green = adc_readn(0, 10);  /* sample channel #0 10 times, take average */
      blue = adc_readn(1, 10);   /* sample channel #1 10 times, take average */
   
      double dgreen = ((double)green) - xc;
      double dblue = ((double)blue) - yc;
      double xmap = wcx[0] * dgreen + wcx[1] * dblue;
      double ymap = wcy[0] * dgreen + wcy[1] * dblue;
   
      awa_measured = atan2(ymap, xmap) * RAD_TO_DEG;
   
      // ...

    

      // Wait for timer signal to begin a new cycle

      

      // ...
   }
}