Arduino – Button – mathcodeprint

The button sketch uses a single button press to light an LED. The button sketch introduces the concept of Input and Conditional execution of code.

Fritzing Diagram ( and Code )

Arduino Sketch ( INO File )

Arduino Sketch ( INO File ) – No Comments Version

How the Momentary PushButton works

12 mm Momentary Push Button Exploded View
figure 2

Pull Down Resistor

A Pull Down Resistor is used on this project to set the “default value” of the Pin on the Arduino. When you desing a circuit you can use a PullDown or a PullUp resistor. The PullDown is a resistor that connects the pin to ground “pulls” the voltage of the pin to Ground. Conceptually it sets the value of the pin to Zero or False. It is therefare a good way to think of it as setting the dfault value to Zero or False.

A PullUp Resistor does to the inverse. The pullup resistor connectors the pin of the Arduino to 5 Volts or 3.3 Volts , dpending on which you are using, to set the default value to One or True.

Materials

Arduino UNO
1 – 5mm LEDs
1 – Momentary Pushbutton
Hookup Wire
Jumper Wires
Breadboard

Coding Directions

Copy the following code into a new sketch. Double check to make certain the PIN assignments match your wiring.

int BUTTON_PIN = 7;
int LED_PIN = 13;
boolean buttonState;

void setup() {
  pinMode( BUTTON_PIN, INPUT );
  pinMode( LED_PIN, OUTPUT );
}

void loop(){

  buttonState  = digitalRead( BUTTON_PIN );

  if ( buttonState )  {
    digitalWrite( LED_PIN, HIGH );
  } else {
    digitalWrite( LED_PIN, LOW );
  }  
}