This sketch demonstrates how to use the Grove momentary button. The momentary button is a digital device (i.e. it can be "on" or "off" only).

03.20_-_Grove_momentary_button.ino

/*  03.020 - Grove momentary button
 *   
   This sketch demonstrates how to use the Grove momentary button.

   The momentary button is a digital device (i.e. it can be "on" or "off" only).
   
   
   Components
   ----------
    
    - Grove Base Shield
    - An Arduino Uno compatible board (such as Arduino/Genuino Uno or Seeeduino)
    - Grove momentary button 
    - One Grove cable
    
    IDE
    ---
    
    Arduino IDE
    
    Libraries
    ---------
    
    - 
    
    Connections
    -----------
    
    Use a Grove cable to connect the temperature module to Base Shield connector D2.
    
    Other information
    -----------------
    
    - Use this sketch along side the video lecture 03.020 of Grove For Busy People
    - Original example sketch location: http://wiki.seeedstudio.com/Grove-Button/
    - Grove component: https://txplo.re/a8cb6
    
    Github Gist
    -----------
    <script src="https://gist.github.com/futureshocked/d53f230adbc249b3a59571575459f1a2.js"></script>
    https://gist.github.com/futureshocked/d53f230adbc249b3a59571575459f1a2
    
    For course information, please go to https://techexplorations.com/product/grove-for-busy-people/
    
    Created on July 5 2019 by Peter Dalmaris
*/

// constants won't change. They're used here to set pin numbers:
const int buttonPin = 4;     // digital pin 4 is on Grove connector D4
const int ledPin =  13;      // the number of the build-in LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    digitalWrite(ledPin, HIGH);
  } else {
    // turn LED off:
    digitalWrite(ledPin, LOW);
  }
}