/*
  Simple LED Toggle
*/

// pin constants
const int BTN_PIN = 8;
const int LED_PIN = 7;

// state variables
bool ledValue = false;
int oldBtnVal = HIGH; // INPUT_PULLUP idles HIGH

void setup() {
  Serial.begin(9600);
  pinMode(BTN_PIN, INPUT_PULLUP);
  pinMode(LED_PIN, OUTPUT);
  Serial.println("Push the button!\n");
}

void loop() {
  int buttonValue = digitalRead(BTN_PIN);
  if (buttonValue != oldBtnVal) {   // button changed
    oldBtnVal = buttonValue;        // remember state
    if (buttonValue == LOW) {       // was just pressed
      Serial.println("Button pressed");
      ledValue = !ledValue;         // invert current ledValue
    } else {
      Serial.println("Button released"); // was just released
    }
    delay(20);  // short delay to debounce button
    digitalWrite(LED_PIN, ledValue);
  }
}