Arduino Smart Home Project for Kids: Circuit and Code

Put it all together. The porch lamp turns on at night, and pressing the doorbell rings the buzzer and opens the door.

Parts you need

• Arduino Uno
• LDR + 10kΩ
• Push button
• Buzzer
• White LED
• SG90 servo

Wiring

1. LDR → A0
2. Doorbell button → pin 2
3. Buzzer → pin 8
4. Servo → pin ~9
5. Lamp LED → pin 13

Arduino code

#include <Servo.h>
Servo door;
int lamp = 13;
int bell = 2;
int buzzer = 8;

void setup() {
  pinMode(lamp, OUTPUT);
  pinMode(bell, INPUT);
  door.attach(9);
  door.write(0);
}

void loop() {
  int light = analogRead(A0);
  if (light < 300) {
    digitalWrite(lamp, HIGH);
  } else {
    digitalWrite(lamp, LOW);
  }

  if (digitalRead(bell) == HIGH) {
    tone(buzzer, 660, 200);
    door.write(90);
    delay(2000);
    door.write(0);
  }
  delay(50);
}

Goal and tip

Goal: Make it dark so the lamp turns on, then ring the doorbell to open the door.

Tip: Try this: keep the door open for 4 seconds instead of 2.

Run this experiment in the free simulator