How to make this code run once in a loop when the button is pressed?

Projects Programming
1

I have a code that I need to be run once only if user presses the button, and after depending on the array generated randomly AD9850 will generate pulses with different frequencies.

  String after[4];
  String before[]={"1000","0100","0010","0001"};
  uint8_t array_size = sizeof(before) / sizeof(before[0]);
  int LED=13;
  int btn=5;
  int btn_state;

void setup() {
  Serial.begin(9600);
  while(!Serial);
  pinMode(LED, OUTPUT);
  pinMode(btn, INPUT_PULLUP);
  btn_state=digitalRead(btn);
  randomSeed(analogRead(0));
  for(int i=0; i<4; i++) {
  
    // ---Pick a random array element.---
    uint8_t pick = random(0, array_size);

    // ---Display the value.---
    //Serial.println(before[pick]);

    // ---Assign the values to after[] array---
    after[i]=before[pick];
    //Serial.println(after[i]);

    // ---Overwrite with the last element of the array.---
    before[pick] = before[array_size - 1];

    // ---Reduce the array size to be selected.---
    array_size--;
    digitalWrite(LED, HIGH);
  }
  
  for (String element : after)
  Serial.println(element);
  
  }


void loop() {
  
}

The problem is that I can not acces thhe array in loop() function, or in any other function as it is a local variable. My "circuit" is here (sorry for simplicity):

изображение

So when the button is pressed random array is generated and displayed on OLED menu, also pulses are generated by AD9850 and with encoder I can change the interval between different LFM pulses.
Thanks in advance.

2

What array are you talking about?

3

before[] array after mixing its elements (in for loop)

4

Array before[] is not a local, it is global variable
What's your problem with it?

5

it is global here

String after[4];
  String before[]={"1000","0100","0010","0001"};
  uint8_t array_size = sizeof(before) / sizeof(before[0]);
  int LED=13;
  int btn=5;
  int btn_state;

but i need this array after being mixed, after this code:

randomSeed(analogRead(0));
  for(int i=0; i<4; i++) {
    // ---Pick a random array element.---
    uint8_t pick = random(0, array_size);

    // ---Assign the values to after[] array---
    after[i]=before[pick];

    // ---Overwrite with the last element of the array.---
    before[pick] = before[array_size - 1];

    // ---Reduce the array size to be selected.---
    array_size--;
  }

before for loop the array before[] is like a sequence for ex. [1,2,3,4] is global, after for loop it becomes mixed for ex. [3,1,2,4] only inside setup() function. I need [3,1,2,4], not [1,2,3,4]. But in loop() function whenever I serial print before[] array, it prints [1,2,3,4].

6

This is not true. By changing an array in setup, you are changing the global array.
If you then print its elements in the loop(), they will be changed

7

Also, your question doesn't match the title at all.

8

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