Creative Tech Course: LED Dimmer ON/OFF Extra Credit - Toggle On/Off

LEDOnOffExtraCredit.ino

/*
  Set the brightness of an LED with a potentiometer
  Use a momentary switch to toggle the LED on (at the brightness set by pot) or off 
  Toggle happens each time the button is pressed to the ON position
 */
 
// These constants won't change.
const int analogInPin = A1;    // Analog input pin that the potentiometer is attached to
const int analogOutPin = 3;   // Analog output pin that the LED is attached to
const int buttonPin = 2;       // the number of the pushbutton pin
 
int sensorValue = 0;          // value read from the pot
int outputValue = 0;          // value output to the PWM (analog out)
int buttonState = 0;          // variable for reading the pushbutton status
 
boolean ledState = LOW;      // should the LED be on or off?
boolean lastButtonState = LOW; // the state of the button last time we checked
 
void setup() {
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);
}
 
void loop() {
  // determine if the button is pressed or not
  buttonState = digitalRead(buttonPin);
 
  // if there's a transition of the button from LOW to HIGH, that's a toggle so swap the LED on/off state
  if (buttonState == HIGH && lastButtonState == LOW) {
      if (ledState == LOW) { // was LOW, change to HIGH
          ledState = HIGH;
      } else { // was HIGH, change to LOW
          ledState = LOW;
      }
  } 
 
  // save the current button state for the next time through the loop
  lastButtonState = buttonState;
 
  // based on the above LED state check, set the LED to be on or off
  if (ledState == HIGH) { // turn the LED on
    // read the analog in value:
    sensorValue = analogRead(analogInPin);            
    // map it to the range of the analog out:
    outputValue = map(sensorValue, 0, 1023, 0, 255);  
    // set the analog out value:
    analogWrite(analogOutPin, outputValue);           
  } else { // turn the LED off
    analogWrite(analogOutPin, 0);   
  } 
 
  // wait 2 milliseconds before the next loop
  // for the analog-to-digital converter to settle
  // after the last reading:
  delay(2);                     
}