Array of classes

Projects Programming
1

Is this possible with Arduino 1.0?

This is what I did:

Library Creation:
I created a folder RobotArm in my library directory and created a new .h file in it (RobotArm.h).

In RobotArm.h I tried to create an array of classes with the code:

AF_DCMOTOR motor[NUM_MOTORS];

Library Modification:
In the motor shield's library AFMotor.cpp, I added a default constructor, and an initialization constructor. (The library only had a constructor with 2 parameters passed to it).

AF_DCMotor::AF_DCMotor()
{
}

For AF_DCMOTOR::init(...) I copied and pasted the parameters and code of AF_DCMOTOR::AF_DCMOTOR(...) (the constructor with 2 parameters passed to it).

Array Initialization:
In my sketch file, I added:

for(int i_motors = 0; i_motors < NUM_MOTORS; i_motors++)
motor[i_motors].init(i_motors+1,1,MOTOR12_64KHZ);

inside of void setup().

When I try to verify my sketch I get the errors:

H:\Arduino\arduino-1.0\libraries\RobotArm/RobotArm.h:58: error: 'AF_DCMOTOR' does not name a type
....
sketch_mar14a.cpp: In function 'void setup()':
sketch_mar14a:6: error: 'motor' was not declared in this scope

The line numbers are the lines of the code I've copied and pasted into my post.

2

Can you post your code? These snippets make it hard to see the real problem. For example, did you include RobotArm.h?

When posting, select the code, and put it between [code] ... [/code] tags.

You can do that by hitting the # button above the posting area.

Normally I wouldn't instantiate objects inside a .h file, that belongs in a .cpp file really. In other words, don't put the array in the .h file.

3

I moved all variable initializations to a .cpp file in my library. This is what I have now:

my sketch:

#include <AFMotor.h>
#include <RobotArm.h>

void setup() {
  
for(int i_motors = 0; i_motors < NUM_MOTORS; i_motors++)
  motor[i_motors].init(i_motors+1,1,MOTOR12_64KHZ);  
  
  for(int i_motor = 0; i_motor < NUM_MOTORS; i_motor++)      
    motor[i_motor].setSpeed(0);
}

void loop() {
  
  motor[0].run(FORWARD);      // turn it on going forward
  delay(10);
  motor[0].run(BACKWARD);     // the other way
  delay(10);
  
}

RobotArm.h:

#include <Arduino.h>

#ifndef RobotArm
#define RobotArm

///////////////////////////  MACROS ///////////////////////////////////////////////

#define MAX_SPEED 1
#define MIN_DV_M1 6.0
#define MIN_DV_M2 6.0
#define MIN_DV_M3 6.0
#define MIN_DV_M4 6.0
#define MOTOR_SUPPLY_VOLTAGE 9.0
#define NUM_MOTORS 4

//////////////////////////////////////////////////////////////////////////////////

///////////////////////////  Struct Types ////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////

struct position_s
{
  int max[NUM_MOTORS];
  int min[NUM_MOTORS];
  int center[NUM_MOTORS];
};

struct speed_s
{
  int max[NUM_MOTORS];
  int min[NUM_MOTORS];
}; 

struct motors_s 
{
  int fb[NUM_MOTORS];
  int fb_pins[NUM_MOTORS];
}; 

//////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////


#endif

RobotArm.cpp

#include <RobotArm.h>

/////////////////////////////// SYSTEM STRUCTS ////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////

 position_s position = 
{
  {245,245,245,245},
  {10,10,10,10},
  {255/2,255/2,255/2,255/2}
};

speed_s speed = 
{
  {1},
  {(MIN_DV_M1/MOTOR_SUPPLY_VOLTAGE*255),(MIN_DV_M2/MOTOR_SUPPLY_VOLTAGE*255),(MIN_DV_M3/MOTOR_SUPPLY_VOLTAGE*255),(MIN_DV_M4/MOTOR_SUPPLY_VOLTAGE*255)},
};

motors_s motors =
{
  {0},{A0,A1,A2,A3}
};

//////////////////////////////////////////////////////////////////////////////////

////////////////////////////// GLOBAL VARIABLES //////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////

AF_DCMOTOR motor[NUM_MOTORS];


//////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////

the relevant part of the modified library AFMotor.cpp (no compilation errors)

AF_DCMotor::AF_DCMotor()
{
}

AF_DCMotor::AF_DCMotor(uint8_t num, uint8_t freq) {
  motornum = num;
  pwmfreq = freq;

  MC.enable();

  switch (num) {
  case 1:
    latch_state &= ~_BV(MOTOR1_A) & ~_BV(MOTOR1_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM1(freq);
    break;
  case 2:
    latch_state &= ~_BV(MOTOR2_A) & ~_BV(MOTOR2_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM2(freq);
    break;
  case 3:
    latch_state &= ~_BV(MOTOR3_A) & ~_BV(MOTOR3_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM3(freq);
    break;
  case 4:
    latch_state &= ~_BV(MOTOR4_A) & ~_BV(MOTOR4_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM4(freq);
    break;
  }
}

void AF_DCMotor::init(uint8_t num, uint8_t freq) {
  motornum = num;
  pwmfreq = freq;

  MC.enable();

  switch (num) {
  case 1:
    latch_state &= ~_BV(MOTOR1_A) & ~_BV(MOTOR1_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM1(freq);
    break;
  case 2:
    latch_state &= ~_BV(MOTOR2_A) & ~_BV(MOTOR2_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM2(freq);
    break;
  case 3:
    latch_state &= ~_BV(MOTOR3_A) & ~_BV(MOTOR3_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM3(freq);
    break;
  case 4:
    latch_state &= ~_BV(MOTOR4_A) & ~_BV(MOTOR4_B); // set both motor pins to 0
    MC.latch_tx();
    initPWM4(freq);
    break;
  }
}

void AF_DCMotor::run(uint8_t cmd) {
  uint8_t a, b;
  switch (motornum) {
  case 1:
    a = MOTOR1_A; b = MOTOR1_B; break;
  case 2:
    a = MOTOR2_A; b = MOTOR2_B; break;
  case 3:
    a = MOTOR3_A; b = MOTOR3_B; break;
  case 4:
    a = MOTOR4_A; b = MOTOR4_B; break;
  default:
    return;
  }

I'm now getting errors:

sketch_mar14a.cpp: In function 'void setup()':
sketch_mar14a:6: error: 'motor' was not declared in this scope
sketch_mar14a:9: error: 'motor' was not declared in this scope
sketch_mar14a.cpp: In function 'void loop()':
sketch_mar14a:14: error: 'motor' was not declared in this scope

I tried moving the array of classes declaration to my sketch instead of the .cpp file and I got the additional error:

sketch_mar14a:3: error: 'AF_DCMOTOR' does not name a type

4

To answer my own questions:

yes it is possible, and

"does not name a type" and "was not declared in the scope" errors refer to the compiler not being able to find something's definition - http://cplusplus.syntaxerrors.info/index.php?title=‘Foo’_does_not_name_a_type

AF_DCMOTOR should have been AF_DCMotor