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How reduce code in arduino

urko18 (59)
Hi everyone!

I am programing in arduino a control of a robotic arm with 4 motors, and I have the same code of movements for each motor, each one with his number variable.

For example, this part of the code corresponds to the 2 motor:

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    //ID2
  if (positionn2[l][i] < initial2)
  {
   while (positionn2[l][i] < initial2)
   {
    before_position_2 = initial2;
    dxlSetGoalPosition(SERVO_ID[1], initial2);
    initial2--;
    delayMicroseconds(400);

     if (initial2 > before_position_2 || initial2 < before_position_2)
     {
      if (initial2 == position2 + MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2++;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
      else if (initial2 == position2 - MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2--;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
    }
    else if (initial2 == before_position_2)
    {
      turns2 = turns2;
    }
   }
  }
  else if (positionn2[l][i] > initial2)
  {
   while (positionn2[l][i] > initial2)
   {
    before_position_2 = initial2;
    dxlSetGoalPosition(SERVO_ID[1], initial2);
    initial2++;
    delayMicroseconds(400);

    if (initial2 > before_position_2 || initial2 < before_position_2)
    {
      if (initial2 == position2 + MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2++;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
      else if (initial2 == position2 - MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2--;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
    }
    else if (initial2 == before_position_2)
    {
      turns2 = turns2;
    }
   }
  }


it is posible to reduce the code? that is, is posible instead of put the same code to each motor (changing the numbers) to put all together in one code "part" in order to clarify and become easier to read the program?

Thank you!
Ganado (6805)

Yes, it is usually always possible to factor out similar code into a function. Factoring out similar functionality helps see the different logical parts of the code, and can further help you reason about what's going on or simplify the logic even more.

Looking at the different sections side-to-side can help see similarities.
Your main differences is less-than comparisons and decrements in one branch, and greater-than comparisons and increments in the other branch, with everything else being the same.

It's possible there's an even simpler solution, but one way to simplify this could be to define a delta value, either positive or negative, that can invert the operations, and then factor the common functionality into a function.

For completeness, you must pass every needed variable as a parameter into a common function.
This might not be necessary if you factor out variables that belong together into a struct/class.

________________________________________

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void common_function(int delta, int& initial2, int& turns2, int& position2,
                     ArrayType positionn2, int l, int i, {fill in what I forgot})
{
    before_position_2 = initial2;
    dxlSetGoalPosition(SERVO_ID[1], initial2);
    initial2 += delta;
    delayMicroseconds(400);

    if (initial2 > before_position_2 || initial2 < before_position_2)
    {
        if (initial2 == position2 + MX_MAX_POSITION_VALUE)
        {
            position2 = initial2;
            turns2++;
            Serial.print("Vueltas 2: ");
            Serial.println(turns2);
        }
        else if (initial2 == position2 - MX_MAX_POSITION_VALUE)
        {
            position2 = initial2;
            turns2--;
            Serial.print("Vueltas 2: ");
            Serial.println(turns2);
        }
    }
}

if (positionn2[l][i] < initial2)
{
    int delta = 1.0;
    while (positionn2[l][i] < initial2)
    {
        common_function(delta, initial2, turns2, position2, positionn2, int l, int i, ...);
    }
}
else if (positionn2[l][i] > initial2)
{
    int delta = -1.0;
    while (positionn2[l][i] > initial2)
    {
        common_function(delta, initial2, turns2, position2, positionn2, int l, int i, ...);
    }
}

________________________________________

However, there is more you can do beyond this.

if (initial2 > before_position_2 || initial2 < before_position_2)
What is the point of this complication? This can be simplified by just saying
if (initial2 != before_position_2)

Note,
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    else if (initial2 == before_position_2)
    {
      turns2 = turns2;
    }

Is this a typo? This section of code doesn't change anything.

Last note,
if (initial2 == position2 + MX_MAX_POSITION_VALUE)
I hope those are integers you're comparing. If those are floating-point numbers, == is not an accurate way to compare them.

Edit: Last last note,
If you are in C and not C++, you'll need to pass the values you want to change within the function by pointer and not by value. Or use a struct and pass that by pointer.
Last edited on
urko18 (59)
Thank you very much for your help Ganado!!!
I'm going to try your advice now to see how it goes!

In the previous post I think I explained badly, I'm sorry but I still do not have a correct level of English.

What I want is to know if I can put the code below (the movements of the 4 engines) in a single function. I've been doing different tests these weeks and I'm not capable.


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 //ID1
  if (positionn1[l][i] < initial1)
  {
   while (positionn1[l][i] < initial1)
   {
    before_position_1 = initial1;
    dxlSetGoalPosition(SERVO_ID[0], initial1);
    initial1--;
    delayMicroseconds(400);

    if (initial1 > before_position_1 || initial1 < before_position_1)
    {
      if (initial1 == position1 + MX_MAX_POSITION_VALUE)
      {
        position1 = initial1;
        turns++;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
      else if (initial1 == position1 - MX_MAX_POSITION_VALUE)
      {
        position1 = initial1;
        turns--;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
    }
    else if (initial1 == before_position_1)
    {
      turns = turns;
    }
   }
  }
  else if (positionn1[l][i] > initial1)
  {
   while (positionn1[l][i] > initial1)
   {
    before_position_1 = initial1;
    dxlSetGoalPosition(SERVO_ID[0], initial1);
    initial1++;
    delayMicroseconds(400);
    if (initial1 > before_position_1 || initial1 < before_position_1)
    {
      if (initial1 == position1 + MX_MAX_POSITION_VALUE)
      {
        position1 = initial1;
        turns++;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
      else if (initial1 == position1 - MX_MAX_POSITION_VALUE)
      {
        position1 = initial1;
        turns--;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
    }
    else if (initial1 == before_position_1)
    {
      turns = turns;
    }
   }
  }

  //ID2
  if (positionn2[l][i] < initial2)
  {
   while (positionn2[l][i] < initial2)
   {
    before_position_2 = initial2;
    dxlSetGoalPosition(SERVO_ID[1], initial2);
    initial2--;
    delayMicroseconds(400);

     if (initial2 > before_position_2 || initial2 < before_position_2)
     {
      if (initial2 == position2 + MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2++;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
      else if (initial2 == position2 - MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2--;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
    }
    else if (initial2 == before_position_2)
    {
      turns2 = turns2;
    }
   }
  }
  else if (positionn2[l][i] > initial2)
  {
   while (positionn2[l][i] > initial2)
   {
    before_position_2 = initial2;
    dxlSetGoalPosition(SERVO_ID[1], initial2);
    initial2++;
    delayMicroseconds(400);

    if (initial2 > before_position_2 || initial2 < before_position_2)
    {
      if (initial2 == position2 + MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2++;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
      else if (initial2 == position2 - MX_MAX_POSITION_VALUE)
      {
        position2 = initial2;
        turns2--;
        Serial.print("Vueltas 2: ");
        Serial.println(turns2);
      }
    }
    else if (initial2 == before_position_2)
    {
      turns2 = turns2;
    }
   }
  }

  //ID3
  if (positionn3[l][i] < initial3)
  {
   while (positionn3[l][i] < initial3)
   {
    before_position_3 = initial3;
    dxlSetGoalPosition(SERVO_ID[2], initial3);
    initial3--;
    delayMicroseconds(400);

    if (initial3 > before_position_3 || initial3 < before_position_3)
    {
      if (initial3 == position3 + MX_MAX_POSITION_VALUE)
      {
        position3 = initial3;
        turns3++;
        Serial.print("Vueltas 3: ");
        Serial.println(turns3);
      }
      else if (initial3 == position3 - MX_MAX_POSITION_VALUE)
      {
        position3 = initial3;
        turns3--;
        Serial.print("Vueltas 3: ");
        Serial.println(turns3);
      }
    }
    else if (initial3 == before_position_3)
    {
      turns3 = turns3;
    }
   }
  }
  else if (positionn3[l][i] > initial3)
  {
   while (positionn3[l][i] > initial3)
   {
    before_position_3 = initial3;
    dxlSetGoalPosition(SERVO_ID[2], initial3);
    initial3++;
    delayMicroseconds(400);

    if (initial3 > before_position_3 || initial3 < before_position_3)
    {
      if (initial3 == position3 + MX_MAX_POSITION_VALUE)
      {
        position3 = initial3;
        turns3++;
        Serial.print("Vueltas 3: ");
        Serial.println(turns3);
      }
      else if (initial3 == position3 - MX_MAX_POSITION_VALUE)
      {
        position3 = initial3;
        turns3--;
        Serial.print("Vueltas 3: ");
        Serial.println(turns3);
      }
    }
    else if (initial3 == before_position_3)
    {
      turns3 = turns3;
    }
   }
  }

  //ID4
  if (positionn4[l][i] < initial4)
  {
   while (positionn4[l][i] < initial4)
   {
    before_position_4 = initial4;
    dxlSetGoalPosition(SERVO_ID[3], initial4);
    initial4--;
    delayMicroseconds(400);

    if (initial4 > before_position_4 || initial4 < before_position_4)
    {
      if (initial4 == position4 + MX_MAX_POSITION_VALUE)
      {
        position4 = initial4;
        turns4++;
        Serial.print("Vueltas 4: ");
        Serial.println(turns4);
      }
      else if (initial4 == position4 - MX_MAX_POSITION_VALUE)
      {
        position3 = initial4;
        turns4--;
        Serial.print("Vueltas 4: ");
        Serial.println(turns4);
      }
    }
    else if (initial4 == before_position_4)
    {
      turns4 = turns4;
    }
   }
  }
  else if (positionn4[l][i] > initial4)
  {
   while (positionn4[l][i] > initial4)
   {
    before_position_4 = initial4;
    dxlSetGoalPosition(SERVO_ID[3], initial4);
    initial4++;
    delayMicroseconds(400);

    if (initial4 > before_position_4 || initial4 < before_position_4)
    {
      if (initial4 == position4 + MX_MAX_POSITION_VALUE)
      {
        position4 = initial4;
        turns4++;
        Serial.print("Vueltas 4: ");
        Serial.println(turns4);
      }
      else if (initial4 == position4 - MX_MAX_POSITION_VALUE)
      {
        position4 = initial4;
        turns4--;
        Serial.print("Vueltas 4: ");
        Serial.println(turns4);
      }
    }
    else if (initial4 == before_position_4)
    {
      turns4 = turns4;
    }
   }
  }
 }
jonnin (11429)
sure. make a function that does the identical code bit against its input parameters. Then call it 4 times with the different values.

like where you have initial1,initial2,initial3, initial 4 just make the parameter initial and pass in initial1, ... etc in each call.

looks like

void doenginething(double initial, double turns, double before_position) //may have other params
{
//redundant code
...blah
if(initial == before_position)
etc...

}

...
//in the code above replace redundant bit with...
doenginething(initial1, turns1, before_position1);
doenginething(initial2, turns2, before_position2);
/// etc 3, 4


urko18 (59)
Thank you for answering jonnin!

I´m trying to do what yo say:

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void repeat_sequence(double initial, double turns, double before_position, double positionn, double position);
    {
    repeat_sequence(initial1, turns1, before_position_1, positionn1, position1);
    repeat_sequence(initial2, turns2, before_position_2, positionn2, position2);
    repeat_sequence(initial3, turns3, before_position_3, positionn3, position3);
    repeat_sequence(initial4, turns4, before_position_4, positionn4, position4);
 
  if (positionn[l][i] < initial)
  {
   while (positionn[l][i] < initial)
   {
    before_position = initial;
    dxlSetGoalPosition(SERVO_ID[0], initial);
    initial--;
    delayMicroseconds(400);

    if (initial != before_position)
    {
      if (initial == position + MX_MAX_POSITION_VALUE)
      {
        position = initial;
        turns++;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
      else if (initial == position - MX_MAX_POSITION_VALUE)
      {
        position = initial;
        turns--;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
    }
   }
  }
  else if (positionn[l][i] > initial)
  {
   while (positionn[l][i] > initial)
   {
    before_position = initial;
    dxlSetGoalPosition(SERVO_ID[0], initial);
    initial++;
    delayMicroseconds(400);
    if (initial != before_position)
    {
      if (initial == position + MX_MAX_POSITION_VALUE)
      {
        position = initial;
        turns++;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
      else if (initial == position - MX_MAX_POSITION_VALUE)
      {
        position = initial;
        turns--;
        Serial.print("Turns: ");
        Serial.println(turns);
      }
    }
   }
  }
 }


But the program gives some errors, I have one question, is it posible to pass Arrays into a function? Because this is the error that the program gives:

cannot convert 'int (*)[m]' to 'double' for argument '4' to 'void repeat_sequence(double, double, double, double, double)'.

Other question, do I have to declare turns, position, positionn, before_position...???

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