undefined reference to Servo

Forum 2005-2010 (read only) Software Development
1

Ok so this has probably been asked loads before, but I am new to arduino development and have googled but cant find the answer via google

so I have my own custom library called ARM

Arm.h

#ifndef Arm_h
#define Arm_h

#include "WProgram.h"
#include "../Servo/Servo.h"

class Arm {
  public: 
    Arm(int servoPin, int motorPin);
    int getPosition();
    void setPosition(int pos);
    
    int getMotorSpeed();
    void setMotorSpeed(int mSpeed);      
};

#endif

and
Arm.cpp

#include "WProgram.h"
#include <Arm.h>
#include <../Servo/Servo.h>


int motorSpeed;
int servoPos;

Servo positionServo;

Arm::Arm(int servoPin, int motorPin) {
      positionServo.attach(servoPin);
}

void Arm::setPosition(int pos) {
  servoPos = pos;
}

void Arm::setMotorSpeed(int mSpeed) {
  motorSpeed = mSpeed;
}

int Arm::getPosition() {
  return servoPos;
}

int Arm::getMotorSpeed() {
  return motorSpeed;
}

then i have a basic sketch that I am trying to play with to see if i can get things working

#include <Arm.h>

// the arms
Arm tester(1, 2);

void setup() {
}

void loop() {
}

which gives the following error(s)

Arm\Arm.cpp.o: In function `__static_initialization_and_destruction_0':
C:\Program Files\arduino\libraries\Arm/Arm.cpp:9: undefined reference to `Servo::Servo()'
Arm\Arm.cpp.o: In function `Arm':
C:\Program Files\arduino\libraries\Arm/Arm.cpp:12: undefined reference to `Servo::attach(int)'

my questions are

why is this?
how do i fix it?
and from previous development experience hard coding the location of Servo.h can't be good surely? if not how do I get around this issue?

my class can be imported via the arduino IDE and works fine if i omit the servo stuff, but the thing I want to make requires a few servos and motorcontrollers (trying to get servos working forst though)

Thanks

Drogo

2

It's been asked many times. The answer is always the same. Include Servo.h in your sketch, too.

3

ah ha! thank you!
now about the path that ive had to hard code?

is this ok? when i push it onto my board (which is at home) will it still know where to look for it? is the structure similar enough for everything to work ok?

4

The compiler creates .o files from your source code, and libraries that you reference, in a temporary directory.

The linker links those .o files together to create a .hex file, in that same directory.

The uploader copies the .hex file onto the Arduino.

The Arduino then knows nothing about where the files on your computer are.