Introduction: Contact Less Switch
Now we all know that the world has a very bad situation and people are scared for touching things.
So during the Lockdowns I made this contactless switch. Which is very easy to make and code.
This is very useful to stop spread of COVID-19.
I am Studying in 9th grade.
Supplies
Step 1: Make the Connections!
- Connect the GND pin of the Ultrasonic to GND pin of Arduino.
- Connect the VCC pin of the Ultrasonic to the 5V pin of the Arduino.
- Connect the TRIGG pin of the Ultrasonic to the Digital pin 9 of the Arduino.
- Connect the ECHO pin of the Ultrasonic to the Digital pin 10 of the Arduino.
- Connect the GND and VCC pin of relay to the GND and 5V pin of Arduino.
- Connect the IN pin of the relay to the Digital pin 2 of Arduino.
- NOTE: The connections in the above Figure is Different.
Step 2: Time to Code!!
Use the Below code to programme the Arduino<br>
bool x = 0; //holds one of two values, true or false int relayPin = 2; //defines PIN 2 as relay const int trigPin = 9; //defines PIN 9 as trigPin of Ultrasonic sensor const int echoPin = 10; //defines PIN 10 as echoPin of Ultrasonic sensor long duration; //defines a variable int distance; //defines a variable void setup() { pinMode(trigPin, OUTPUT); //sets trigPin as OUTPUT pinMode(echoPin, INPUT); //sets echoPin as INPUT pinMode(relayPin, OUTPUT); //sets relayPin as OUTPUT Serial.begin(9600); //starts the Serial Communication } void loop() { digitalWrite(trigPin, LOW); // Clears the trigPin delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); // Sets the trigPin on HIGH state for 10 micro seconds digitalWrite(trigPin, LOW); // Reads the echoPin, returns the sound wave travel time in microseconds duration = pulseIn(echoPin, HIGH); distance = duration * 0.034 / 2; // Calculating the distance Serial.print("Distance: "); // Prints the distance on the Serial Monitor Serial.println(distance); // The minimum distance needed to activate the switch if (distance < 10) { x = !x; if (x == 0) { digitalWrite(relayPin, HIGH); // ON the Light Serial.println("Light is OFF"); //prints light is OFF } } if (x == 1) { digitalWrite(relayPin, LOW); // OFF the Light Serial.println("Light is ON"); //prints light is ON } delay(500); }<br>
Attachments
Step 3: Upload the Code and Test Them OUT!!!!
Plug the arduino to the computer and upload the code.
If you Like the Project Please VOTE me to the "CAN'T TOUCH THIS" CONTEST

Participated in the
"Can't Touch This" Family Contest
3 Comments
Question 2 years ago
it does not work. the relay goes on off on off on off.
2 years ago
Makes sense, looks useful! But picture this: you have a bunch of arduinos around your room, easily the small Attiny85 or Wemos D1 mini boards (they are very cheap and you only need a couple of pins, right), was with a laser sensor (a detector). And you have a laser pointer around your bed. Wouldn`t it be cool to do things depending on what of the sensors you aim?
Or better yet, have the same with IR sensors and an old TV remote as I have it. :d)
...or for a DIY remote look at https://www.instructables.com/How-to-Add-an-IR-Remote-to-a-Speaker-System/. ;o)
3 years ago
Thanks for sharing :)