This is a detector that will remind the parents when their children place their finger too close to the fan. If the children's fingers are too close to the fan; it might cause serious injuries. So I made this project because I think it will be a good way to prevent the children from putting their fingers into the fan. The parents can easily notice the sound of the detector and immediately take away their children from the fan.

Supplies

In order to make the detector, you would need to prepare the following materials:

1. Breadboard x1

2. Arduino Leonardo/ Uno x1

3. 5V Buzzer x1

4. Ultrasonic distance sensor x1

5. wires x6

Tools:

1. box x1(A random box that could fit your final project. I used a box with 22*12*8cm and it just fits.)

2. Pencil x1

3. Acrylic Turpentine

4. paint brush x1 (you may want to choose the larger one, it'll be easier to paint the entire box)

5. Utility Knife

6. scissor

Step 1: Step 1: Assembling the Components

In this part, you would need to complete a few steps.

First Step: Connect the basic outset

Connect the red wire from 5V to the hole that has a positive sign(+) on the breadboard.

Connect the black wire from GND to the hole that has a negative sign(-) on the breadboard.

Buzzer: Connect the Positive terminal with pin 8 of Arduino and negative terminal to GND (digital).

Ultrasonic Sensor: Connect the VCC to the hole that has a negative sign(-) on the breadboard. Connect the Trigger pin to pin 9 and Echo pin to pin 10 of Arduino. Connect GND of the Ultrasonic Sensor to the hole that has a negative sign(-) on the breadboard.

Second Step: Connect the ultrasonic distance sensor

Third Step: Connect the Buzzer

Buzzer: Connect the Positive terminal with pin 8 of Arduino and negative terminal to GND (digital).

Step 2: Step 2: Coding

Notes: You can copy the code from here

int UltrasonicSensorCM(int trigPin, int echoPin) //Ultrasonic Sensor Code Auto Generated Return CM max distance 200

{

long duration;

pinMode(trigPin, OUTPUT);

pinMode(echoPin, INPUT);

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

digitalWrite(trigPin, HIGH);

delayMicroseconds(20);

digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

duration = duration / 59;

if ((duration < 2) || (duration > 100)) return false;

return duration;

}

void setup(){ // put your setup code here, to run once:

digitalWrite( 9 , LOW ); //set ultrasonic sensor trigPin

}

void loop(){ // put your main code here, to run repeatedly:

if ( UltrasonicSensorCM( 9 , 10 ) == 0 ) {

tone(8, 25, 500); //buzzer or speaker frequency

}

else {

noTone(8); //stop generating the tone

}

Step 3: Step 3: Decorate

For this section, you can cover your project with a protective covering or decoration. So the wires, ultrasonic distance sensor, and the buzzer will not fall down easily. I choose to cover my project with a box that can open easily. So if the project has problems, I'm able to fix the problems quicker.

For the Box:

1. Choose a random box that can fit your project, but its maximum size should not be over the size of the place you want to put on the fan. I used a box with 22*12*8cm.

2. Cut a hole that is a bit larger than the ultrasonic distance sensor, so it can successfully sense the fingers.

3. Cut a smaller hole beside the box that can fit your wire connect to the computer

4. Paint the box with Acrylic Turpentine.

5. Let the box dry.

6. Put the final project inside the box

7. Finish!!!!!!