GPIO Array not working properly.

Using Arduino Programming Questions
#1

Hi all, i’m using several GPIO’s in Arduino mega due to large number of IO i’m using array to declare pins and enable it’s output using for-loop, code for same mentioned below.

//.......Declaring Relays...............//
const int Part1Relays[] ={0, 1, 2, 3, 4, 5, 6, 7};
const int Part2Relays[] ={14, 15, 16, 17, 18, 19, 20, 21};
const int Part3Relays[] ={23, 25, 27, 29, 31, 33, 35, 37};

//.............Command Functions.............//

void Part1Cmd(){
    for (int RelayPin = 0; RelayPin < PinCount; RelayPin++){
    digitalWrite(Part1Relays[RelayPin], LOW);
    }
  }

  void Part2Cmd(){
    for (int RelayPin = 0; RelayPin < PinCount; RelayPin++){
    digitalWrite(Part2Relays[RelayPin], LOW);
    }
  }

  void Part3Cmd(){
    for (int RelayPin = 0; RelayPin < PinCount; RelayPin++){
    digitalWrite(Part3Relays[RelayPin], LOW);
    }
  }

But something unpredictable is happening whenever i change declared pin no. in array either it does not enable all the declared pin or enable all pins irrespective of defined one. I don’t understand why this happens at first it was working perfectly but as soon i modify pin numbers inside array it start working improperly. Please help what could be the issue whether i have to define size of array or there is something else??

#2

This is not valid in the C++ language:

    digitalWrite(Part2Relays[11, 12, 13, 14, 15, 16, 17, 18], LOW);

It may compile, but it doesn't do what you think it does.

You had the first one "Part1Cmd()" right, do the other two the same, correct way. :0

#3

Follow this same format for part2 and part3

    for (int RelayPin = 0; RelayPin < PinCount; RelayPin++){
    digitalWrite(Part1Relays[RelayPin], LOW);
    }

Those could all be byte as the values are <= 255, no need for them to be int (-32768 to 32767), or unsigned int (0 to 65535). Save a byte of memory on each one, might come in handy one day.

#4

One thing more i noted when i delete all array’s and rewrite them it again start working properly and when again i make changes to pins it start behaving abnormally!!! I don’t understand why this is happening…

#5

You haven't posted enough to say.

Are you suggesting that this does not work?

digitalWrite(Part1Relays[1], LOW); // where 0 to 7 can be used

:
:
digitalWrite(Part1Relays[1], HIGH);
#6

CrossRoads:
You haven't posted enough to say.

Are you suggesting that this does not work?

digitalWrite(Part1Relays[1], LOW); // where 0 to 7 can be used

:
:
digitalWrite(Part1Relays[1], HIGH);




As mentioned earlier i'm using Arduino pins using an array and calling several function based on required operations of pins but as whenever i edit or make changes in array declaration like changing pin nos. it start behaving improperly. what could be the reason?

//.......Declaring Relays...............//
const int Part1Relays ={0, 1, 2, 3, 4, 5, 6, 7};
const int Part2Relays ={14, 15, 16, 17, 18, 19, 20, 21};
const int Part3Relays ={23, 25, 27, 29, 31, 33, 35, 37};

#7

Nobody can ever tell you the reason unless you post the entire sketch.

#8