airhorn_button.ino

/*
 * Copyright 2020 Google Inc. All Rights Reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
 
#include <WebUSB.h>

/**
 * Follow the instructions on https://github.com/webusb/arduino/ to install
 * the library and get the Arduino IDE to build and install it correctly.
 */
WebUSB WebUSBSerial(1 /* https:// */, "webusb-horn.firebaseapp.com");

#define Serial WebUSBSerial

const int ledPin = 13;
const int buttonPin = 2;
int previousButtonState = 0;

void setup() {
  while (!Serial) {
    ;
  }
  Serial.begin(9600);
  Serial.write("Sketch begins.\r\n> ");
  Serial.flush();
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop() {
  if (Serial) {
    int buttonState = digitalRead(buttonPin);
    if (buttonState != previousButtonState) {
      if (buttonState == HIGH) {
        digitalWrite(ledPin, HIGH);
        Serial.write("ON\r\n");
      } else {
        digitalWrite(ledPin, LOW);        
        Serial.write("OFF\r\n");        
      }
      Serial.flush();
    }
    previousButtonState = buttonState;
    delay(10);   
  }
}