Blinky-Estop

// Katya Soltan
// Onboard LED blinks until a switch (or an E-stop button) is pressed.
// When the button is released, the LED will resume blinking.
// Make sure to connect a resistor between power and GND on the button to avoid burning it out.
#define switchPin 10
#define LEDPin 13
boolean isLEDOn = false;

void setup() {
  Serial.begin(9600);
  pinMode(switchPin, INPUT);
  pinMode(LEDPin, OUTPUT);
}

void loop() {
  // When the switch is pressed, the pin will read 0, as the circuit completes the loop to GND
  // When the switch is not pressed, the pin will read 1, as the voltage doesn't got to GND
  if(digitalRead(switchPin)){
    // Switch is pressed, LED should be OFF
    digitalWrite(LEDPin, LOW);
  }else{
    // Switch is not pressed, LED should be ON and BLINKING
    if(isLEDOn){ // if the LED is currently on, turn it off
      digitalWrite(LEDPin, LOW);
      isLEDOn = false; // Update LED state
    }else{ // otherwise, turn the LED on to blink it
      digitalWrite(LEDPin, HIGH);
      isLEDOn = true; // Update LED state
    }
  }
  delay(50); // LED blinks every 50ms.
}