further details on my failed attempts to write function values to arrays

[RoBu_286116]

Hi again folks. I've sent you a simplified test program, including what works and what does not. Type of psoc and version of creator are irrelevant, but I'm using a psoc5, creator version 3.3 (less clutter than latest version).  By the way, variables declared at the top are supposed to be global, so the function call should not care.  

Any ideas ?     So, how come I cannot put math function calls inside a DO loop ?  I also tried rewriting this using just IF statements, and it also failed. Try it yourself ! Nice staircase function using only the first of the three functions.

// 2/25/20 BB. This simplified test program is done to show how to be able to generate

// a multipoint waveform to modify various acquired data sets.

#include <project.h>

#include <math.h>

int main()

{

double A;

double B;

uint8 n; 

VDAC8_1_Start();

// The top design of this test program merely has a vdac wired to an output pin.

// If the first of the three commented statements listed below is uncommented,

// then the oscilloscope shows a nice staircase waveform. Either of the other

// two statements fail to compile, which is the goal. 

for(;;) 

  {

  for(n=1;n<=10;n=n+1)

  {

  //A=A+10.0; This statement here compiles correctly

  //A=cos(A); This statement here does not compile correctly

  //A=exp(A); This statement here does not compile correctly 

  VDAC8_1_SetValue(A);

  CyDelay(10);

  if(n==10)

  A=1.0;

  }

  }

}

/* [] END OF FILE */

[MotooTanaka]

Hi,

I tested using CY8CKIT-059

schematic

pins

main.c

===========

#include "project.h"

#include "stdio.h"

#include "math.h"

#ifndef M_PI

#define M_PI 3.14159

#endif

#define STR_LEN 64

char str[STR_LEN+1] ;

void print(char *str)

{

    UART_PutString(str) ;

}

void print_as_float(double v)

{

    if (v < 0.0) {

        v = -v ;

        snprintf(str, STR_LEN, "-%d.%03d ",

            (int)v, (int)(v * 1000) % 1000 ) ;

    } else {

        snprintf(str, STR_LEN, "%d.%03d ",

            (int)v, (int)(v * 1000) % 1000 ) ;

    }

    print(str) ;       

}

int main(void)

{

    double A = 1.0 ;

    double B = 1.0 ;

    uint8_t n ;

    CyGlobalIntEnable; /* Enable global interrupts. */

    UART_Start() ;

    for(;;)

    {

        for (n = 1 ; n <= 10 ; n++) {

            A = cos(M_PI * n / 10.0) ;

            B = exp(5.0 / n) ;

           print_as_float(A) ;

           print_as_float(B) ;

           print("\n") ;

            if (n == 10) {

                A = 1.0 ;

                B = 1.0 ;

            }

        }

        CyDelay(1000) ;

    }

}

===========

Tera Term log

moto

[odissey1 · Accepted solution]

RoBu,

You didn't attach project archive, so my guess that in Project->Build Settings->Linker->additional libraries->add "m" (math)

/odissey1