Library Code - .cpp and .h

Projects Programming
1

Hi All,

I thought that I would have a go at developing my own library, so that a large section of code is hidden away in a library.

But I am getting an error messages when I try and compile it:-

motor.h:16:24: warning: ISO C++ forbids declaration of 'init' with no type [-fpermissive]
init(int, int, int);

motor.cpp:1:0:
H:\Arduino\libraries\Motor\motor.h:16:24: warning: ISO C++ forbids declaration of 'init' with no type [-fpermissive]
init(int, int, int);

motor.cpp:5:1: error: expected initializer before 'void'
void motor::init(int pwm, int in1, int in2) {

motor.cpp:29:23: error: no 'void motor::forward()' member function declared in class 'motor'
void motor::forward() {
^

motor.cpp:33:20: error: no 'void motor::back()' member function declared in class 'motor'
void motor::back() {

motor.cpp:37:1: error: expected declaration before '}' token
};
^

Here is the code that I have in the motor.h file

#ifndef MOTOR_H
#define MOTOR_H
#include <Arduino.h>

  struct motor{
    int pwmPin;
    int inPin1;
    int inPin2;

  public: 
    motor( int, int, int);
    void setDirection(boolean, boolean);
    void stop();
    void speed(int);
  private:
     init(int, int, int);
  };
#endif

And here is the code for the motor.cpp file

#include "motor.h"

motor:: motor(int pwmPin, int inPin1, int inPin2)
  
void motor::init(int pwm, int in1, int in2) {
    pwmPin = pwm;
    inPin1 = in1;
    inPin2 = in2;
    pinMode(inPin1, OUTPUT);
    pinMode(inPin2, OUTPUT);
    stop();
  }
  void motor::setDirection(boolean in1, boolean in2) {
    digitalWrite(inPin1, in1);
    digitalWrite(inPin2, in2);
  }
  void motor::stop() {
    digitalWrite(inPin1, LOW);
    digitalWrite(inPin1, LOW);
    speed(0);
  }
  void motor::speed(int aSpeed) {
    if (aSpeed >= 0) {
      analogWrite(pwmPin, aSpeed);
    }
  }
  // The following functions are not used here
  // but could be useful in future
  void motor::forward() {
    digitalWrite(inPin1, HIGH);
    digitalWrite(inPin1, LOW);
  }
  void motor::back() {
    digitalWrite(inPin1, LOW);
    digitalWrite(inPin1, HIGH);
  }
};

I have looked at several different posts with the same error, but I can't seem to see why I am getting this error. I know it is the syntax of the motor definition, but more than that, I'm not 100% sure.

Never written a library before......

2

Try these codes and compare with yours to see the differences.

motor.h

#ifndef MOTOR_H
#define MOTOR_H
#include <Arduino.h>

struct motor {
    int pwmPin;
    int inPin1;
    int inPin2;

  public:
    motor( int pwmPin, int inPin1, int inPin2);
    void setDirection(boolean, boolean);
    void stop();
    void speed(int);
    void motor::forward();
    void motor::back();
  private:
    void init(int pwm, int in1, int in2);
};
#endif

motor.cpp

#include "motor.h"

motor:: motor(int pwmPin, int inPin1, int inPin2);

void motor::init(int pwm, int in1, int in2) {
  pwmPin = pwm;
  inPin1 = in1;
  inPin2 = in2;
  pinMode(inPin1, OUTPUT);
  pinMode(inPin2, OUTPUT);
  stop();
}

void motor::setDirection(boolean in1, boolean in2) {
  digitalWrite(inPin1, in1);
  digitalWrite(inPin2, in2);
}

void motor::stop() {
  digitalWrite(inPin1, LOW);
  digitalWrite(inPin1, LOW);
  speed(0);
}

void motor::speed(int aSpeed) {
  if (aSpeed >= 0) {
    analogWrite(pwmPin, aSpeed);
  }
}

// The following functions are not used here
// but could be useful in future
void motor::forward() {
  digitalWrite(inPin1, HIGH);
  digitalWrite(inPin1, LOW);
}

void motor::back() {
  digitalWrite(inPin1, LOW);
  digitalWrite(inPin1, HIGH);
}
3

Thanks for that.

So I had missed out "Void" in front of "init" in motor.h?

I've changed that and now I am getting the following when I compile:-

H:\Arduino\libraries\Motor\motor.cpp:3:49: warning: declaration of 'motor::motor(int, int, int)' outside of class is not definition [-fpermissive]
motor:: motor(int pwmPin, int inPin1, int inPin2);
^
H:\Arduino\libraries\Motor\motor.cpp:33:6: error: prototype for 'void motor::forward()' does not match any in class 'motor'
void motor::forward() {
^~~~~
In file included from H:\Arduino\libraries\Motor\motor.cpp:1:0:
H:\Arduino\libraries\Motor\motor.h:15:10: error: candidate is: void motor::forward(boolean, boolean)
void forward(boolean, boolean);
^~~~~~~
H:\Arduino\libraries\Motor\motor.cpp:38:6: error: prototype for 'void motor::back()' does not match any in class 'motor'
void motor::back() {
^~~~~
In file included from H:\Arduino\libraries\Motor\motor.cpp:1:0:
H:\Arduino\libraries\Motor\motor.h:16:10: error: candidate is: void motor::back(boolean, boolean)
void back(boolean, boolean);
^~~~

exit status 1

Compilation error: exit status 1

Any ideas please?

4

Please compare everything.

It wasn't just the "void" that you forgot.

You defined the types of variables but did not inform which variables.

See here:

5

what class is motor declared in? (what is public in reference to)?

6

thinking it gets optimized away..
tried creating object in setup reveals errors..
made some changes until it compiled..

Revised simm..

good luck.. ~q

7

That's permissible in a function's prototype, but not it's implementation.

This one:

That function needs a return type.

9

where is the return type specified for init() ?

10

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.