Digital Reading from a array without using the exact element

Question

Is it possible to read a digital input from an array without using the exact element? Such as

   while(digitalRead(myButtonArray[i]))
     digitalWrite(myLEDArray[i], HIGH);

Reading the myButtonArray one by one and turning on the led one by one doesnt make for clean written code. The following is just an example code. When button on pin 2 which is element 0 is pressed turn on led on pin 7 and turn off when released. When button on pin 3 is pressede turn on led on pin 8 and turn off when released and continue on in the same fashion with the rest of the buttons and leds as well.

 int myButtonArray[] = {2,3,4,5,6};
 int myLEDArray[] = {7,8,9,10,11};

 void setup() {
   for(int i = 0;i<5;i++){
     pinMode(myButtonArray[i], INPUT);
     pinMode(myLEDArray[i], OUTPUT);
   }

 }

 void loop() {
 while(digitalRead(myButtonArray[0]))
      digitalWrite(myLEDArray[0], HIGH);

 while(digitalRead(myButtonArray[1]))
      digitalWrite(myLEDArray[1], HIGH);

 while(digitalRead(myButtonArray[2]))
      digitalWrite(myLEDArray[2], HIGH);

 while(digitalRead(myButtonArray[3]))
      digitalWrite(myLEDArray[3], HIGH);

 while(digitalRead(myButtonArray[4]))
      digitalWrite(myLEDArray[4], HIGH);     
 }

Answer 1

Is this what you want?

 #define NUM_ITEMS 5
 int myButtonArray[NUM_ITEMS] = {2,3,4,5,6};
 int myLEDArray[NUM_ITEMS] = {7,8,9,10,11};

 void setup() {
   for(int i = 0;i<NUM_ITEMS;i++){
     pinMode(myButtonArray[i], INPUT);
     pinMode(myLEDArray[i], OUTPUT);
   }

 }

 void loop() {
     for (int i=0 ; i<NUM_ITEMS ; ++i) {
         while(digitalRead(myButtonArray[i]))
              digitalWrite(myLEDArray[i], HIGH);
         digitalWrite(myLEDArray[i], LOW);
     }
 }

Answer 2

I think, you did not realized, that digitalWrite(i,value) sets the pin i to value AND the pin have the value until set otherwise. So you probabelly want something like this:

void loop() {
  for (int i=0;i<5;i++) 
    digitalWrite(myLEDArray[i], digitalRead(myButtonArray[i]));
}

where each LED follows each respective Button both HIGH and LOW.

Answer 3

It isn't clear from the question or the code what you actually want to do. Perhaps back up a step: edit the question and write a clear-cut problem specification.

For example, a specification for what the code you have actually does, is:

For each of five buttons,

If button k is on, turn on LED k, and stall in a loop until button k is released. Leave LED k on when the button is released.

Answer 4

In your question you wrote

and turn [the LED] off when [the corresponding button is] released

and yet you never turn the LEDs off in your code. Then, I assume the code in your question is irrelevant, and you just want the LEDs to show the states of the buttons at all times. This can be done by writing to the LEDs the values you read from the buttons. Do this for each button/LED pair, and loop over the pairs:

void loop() {
    for (int i = 0; i < 5; i++)
        digitalWrite(myLEDArray[i], digitalRead(myButtonArray[i]));
}