Year 2 - The internet of things

In this unit we will see how to create a motion detector with an Arduino board. A useful object in order to detect when there is something moving in a room. This kind of object is typically used in hotels when there is no employee at the reception and they want to be notified when a guest is coming.

As we will need to connect this object to the internet we won't use the Arduino Uno board but instead the

We will see in this course how you can also connect it to the internet in order to make it even more valuable.

What we will need:

• Arduino Node MCU.
  
• PIR motion sensor.
• 3 male to female jumper cables.
  

Optionnal:

• 1 led (you can also use the one of the Arduino card but it is smaller)
• 1 male to male jumper cable (optionnal).
• 1 resistor to avoid your LED to burn.
  

From: https://www.instructables.com/id/NodeMCU-ESP8266-Details-and-Pinout/

Here is the code:

int led = 12;  // we are inserting the led on the pin 12 which is pin D6 on esp
int sensor = 13;  // we are inserting the pir on the pin 13 which is pin D7 on esp
void setup() { // initial status of the Arduino board
  pinMode(sensor, INPUT);   // declare sensor as input
  pinMode(led, OUTPUT);  // declare led as output
  Serial.begin(115200); // frequence at which the messages will be written in the console
}
void loop() { // what the Arduino will do continuously
  long state = digitalRead(sensor); // a variable named state takes the value of the sensor
    if(state == HIGH) { // if there is something passing through
      digitalWrite (led, HIGH); // put the led on
      Serial.println("Motion detected!"); // print the message motion detected
      delay(2000); // wait 2 seconds
    }
    else { // if nothing is passing through
      digitalWrite (led, LOW); // let the led off
      Serial.println("Motion absent!"); // display a message saying that there is no motion detected
      delay(2000); // wait 2 seconds
      }
}