ex_admm_stats.c

TI公司的CCS一些常用的函数库

/////////////////////////////////////////////////////////////////////////
////                          EX_ADMM_STATS.C                        ////
////                                                                 ////
////  This program displays the min and max of 50 A/D conversions.   ////
////  The process is repeated forever.                               ////
////                                                                 ////
////  Configure the CCS prototype card as follows:                   ////
////     Insert jumpers from 9 to 15                                 ////
////     Use the #9 POT to vary the voltage.                         ////
////     See additional connections below.                           ////
////                                                                 ////
////  This example will work with the PCM and PCH compilers.  The    ////
////  following conditional compilation lines are used to include a  ////
////  valid device for each compiler.  Change the device, clock and  ////
////  RS232 pins for your hardware if needed.                        ////
/////////////////////////////////////////////////////////////////////////z
////        (C) Copyright 1996,2001 Custom Computer Services         ////
//// This source code may only be used by licensed users of the CCS  ////
//// C compiler.  This source code may only be distributed to other  ////
//// licensed users of the CCS C compiler.  No other use,            ////
//// reproduction or distribution is permitted without written       ////
//// permission.  Derivative programs created using this software    ////
//// in object code form are not restricted in any way.              ////
/////////////////////////////////////////////////////////////////////////

#if defined(__PCM__)
#include <16F877.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)  // Jumpers: 8 to 11, 7 to 12

#elif defined(__PCH__)
#include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)  // Jumpers: 8 to 11, 7 to 12
#endif


float sqrt(float x);
float fabs(float x);

main() {

	int1 loopDoneFlag;
	int i,value[50],min,max,tempSum,numberOfSamples=51;
	float standardDeviation, mean;

   printf("EX_ADMM\r\nSampling:");

   setup_port_a( ALL_ANALOG );
   setup_adc( ADC_CLOCK_INTERNAL );
   set_adc_channel( 0 );


   while (TRUE)
	{
      loopDoneFlag = 0;
      min=255;
      max=standardDeviation=tempSum=0;

		for(i=0;i<50;++i)
      {
         delay_ms(10);
         value[i] = Read_ADC();
   	}

		for(i=0;i<50;++i)
		{
         if (value[i]<min)	min=value[i];
         if (value[i]>max)	max=value[i];
			mean+=value[i];
		}

		mean /= numberOfSamples;

		for(i=0;i<50;++i)
		{
         tempSum = fabs(value[i] - mean);
			standardDeviation += tempSum;
		}

		standardDeviation /= numberOfSamples;
		standardDeviation = sqrt(standardDeviation);

		loopDoneFlag = 1;

      printf("\n\rMin: %2U  Max: %2U  Mean: %2F Std.Dev: %2F\r\n",
			min,max,mean,standardDeviation);
   }
}


float fabs(float x)
{
	if(x < 0)
		return(x*-1);
}

float sqrt(float x)
{
   float y, res;
   byte *p;

   #ifdef _ERRNO
   if(x < 0)
   {
      errno=EDOM;
   }
   #endif

   if( x<=0.0)
      return(0.0);

   y=x;
   p=&y;
   (*p)=(byte)((((int16)(*p)) + 127) >> 1);

   do {
      res=y;
      y+=(x/y);
      (*p)--;
   } while(res != y);

   return(res);
}