Arduino: Toggle LED with breadboard push button

mega-switched-led-components.svg

toggle-led-pushbutton.ino

/*
  Button toggles LED off and on

  Using an Arduino MEGA 2560 (from here on referred to as the MEGA)
  and associated electronic components, create a hardware and software solution that 
  will turn on an LED when a momentary button is pressed and then turn off the light 
  when the button is pressed again.

  The circuit:
  - LED attached from pin 12 with inline 1k Ω to ground
  - pushbutton attached to pin 9 from +5V to ground

  created 2020-01-19
  Steven Combs (https://www.stevencombs.com)
*/

// Integer variables

int ledPin = 12; // LED to PIN 12 (+5V) to ground on MEGA
int buttonPin = 9; // Button on PIN 9 (+5V) to ground on MEGA
int toggleState = false; // Button toggle is off

void setup() // Configure devices
{
  pinMode(ledPin, OUTPUT); // ledPin as output device
  pinMode(buttonPin, INPUT_PULLUP); // buttonPin as input with a pullup resistor
}

void loop() // Main loop
{
  if (digitalRead(buttonPin) == false) { 
  toggleState = !toggleState; // Reverse current state of variable (false <-> true)
  digitalWrite(ledPin, toggleState); // LED to toggleState
  } 
  while (digitalRead(buttonPin) == false);
  delay(50); // Add a necessary time delay of 50ms
}