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## setup()

The setup() function is called when a sketch starts. Use it to initialize variables, pin modes, start using libraries, etc. The setup function will only run once, after each powerup or reset of the Arduino board.

### Example

    int buttonPin = 3;

    void setup()
    {
      Serial.begin(9600);
      pinMode(buttonPin, INPUT);
    }

    void loop()
    {
      // ...
    }

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The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.

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