Search code examples
cavrcodevisionavr

error function declared but never defined

I have added a library to my c project in codeVision AVR. when I want to use it's functions receive this error: function 'function name' is declared but never defined. here is my code:

#include "pid.h"
#include <mega32.h>
PidType _pid;
void main(void)
{
//some uC hardware initializing codes which are removed here to simplify code
PID_Compute(&_pid);
while (1)
  {
  // Place your code here

  }
}

in pid.h:

.
.
bool PID_Compute(PidType* pid);
.
.

and pid.c:


#include "pid.h"
.
.
bool PID_Compute(PidType* pid) {
  if (!pid->inAuto) {
    return false;
  }
    FloatType input = pid->myInput;
    FloatType error = pid->mySetpoint - input;
    pid->ITerm += (pid->ki * error);
    if (pid->ITerm > pid->outMax)
      pid->ITerm = pid->outMax;
    else if (pid->ITerm < pid->outMin)
      pid->ITerm = pid->outMin;
    FloatType dInput = (input - pid->lastInput);

    FloatType output = pid->kp * error + pid->ITerm - pid->kd * dInput;

    if (output > pid->outMax)
      output = pid->outMax;
    else if (output < pid->outMin)
      output = pid->outMin;
    pid->myOutput = output;


    pid->lastInput = input;
    return true;
}

the ERROR:

function 'PID_Compute' declared, but never defined.

Where is the problem?

EDIT:

to add the library to my project I placed the .c and .h library files in the same folder that my main project file is:

enter image description here

and then #include "pid.h" in my main file:

#include "pid.h"
#include <mega32.h>

// Declare your global variables here
PidType _pid;
void main(void)
{
.
.

my error and warnings: enter image description here

enter image description here

enter image description here

EDIT2: I simplified the code and now can show you the entire code: main code:

#include "pid.h"
PidType _pid;
void main(void)
{
PID_Compute(&_pid);
while (1)
      {

      }
}

pid.h:

#ifndef PID_H
#define PID_H

#include <stdbool.h>

typedef struct {
 int i;
} PidType;


bool PID_Compute(PidType* pid);

#endif

pid.c:

#include "pid.h"
bool PID_Compute(PidType* pid) {

    pid->i = 2;
    return true;
}
Solution

  • thank you every body. As you said, the pid.c was not added to the project. for those who may face the same problem: in codeVision AVR we have to add .c file to project from project->configure->files->input files->add

    I addec .c file to project and the error went away.