THE STORY OF SD-CARD

Our project is about a device that maintains social distancing.

The Beginning for innovation

Once the schools and offices reopen it will increase the risk of getting COVID-19. The only way we can decrease this risk is by maintaining social distancing. We started brainstorming on solutions through which we can make a device that not only maintains social distancing but is portable at the same time. Due to lockdown, we were limited with the resources available with us and hence we had to build something easily available. We started off something that can be easily implemented with less use of hands. We researched a lot and studied different kinds of sensors that can calculate the distance between 2 or more bodies. We studied from different sensor guide books and watched videos on YouTube from the channel of Arduino.

Personal Safety through Proximity Sensing

Designed during the global pandemic, the SD-Card (Social Distancing Card) is a wearable Arduino-based safety device. Its primary purpose is to act as a physical reminder of the 6-foot distancing guideline, providing real-time haptic and visual feedback to the wearer when a proximity violation occurs.

Core Hardware Components

• Arduino Nano R3: The brain of the operation, selected for its small form factor which makes it ideal for wearable projects.
• HC-SR04 Ultrasonic Sensor: This sensor works by emitting high-frequency sound waves. It captures the "echo" as the waves bounce off nearby objects, allowing the Arduino to calculate the exact distance in centimeters or inches.
• Piezo Buzzer: Provides a clear audible alert when an object or person enters the "danger zone".
• Bi-Color Feedback (LEDs): A Green LED signifies that the environment is clear and social distancing is being maintained. A Red LED lights up immediately when someone comes within the 6-foot threshold.
• SG90 Micro-Servo: Can be programmed to physically toggle a sign or move a mechanical indicator for additional alerting.

System Logic and Distance Calculation

The code written in the Arduino IDE follows a simple but strict logic loop:

1. Send Trigger Pulse: The Arduino sends a 10-microsecond pulse to the HC-SR04 Trigger pin.
2. Measure Echo Time: The sensor returns a pulse on the Echo pin. We use pulseIn() to measure the duration of this pulse.
3. Calculate Distance: Using the speed of sound (approximately 0.034 cm/µs), the duration is converted to distance: Distance = (Duration * 0.034) / 2.
4. Conditional Alerting:
   • IF Distance <= 183cm (approx. 6 feet) -> Activate Buzzer + Red LED.
   • ELSE -> Green LED remains on, Buzzer stays silent.

This loop repeats hundreds of times per second, ensuring constant vigilance over the wearer's surroundings.

HOW THE-CARD WORKS

After a week of research, brainstorming and studying we ended up making, the SD-CARD (social distancing card). The SD-CARD consists of an Arduino Nano which is connected with a buzzer, an ultrasonic sensor and 2 LEDs. The ultrasonic sensor calculates the distance between the person wearing it and people near him/her. If the person is not maintaining social distancing i.e. if the person is less than 6 feet apart then the buzzer will start buzzing and alert the person. There are two LEDs red and green. Red LED turns on when social distancing isn't maintained and greed LED turns on when the distance is maintained. The entire device is powered by a 9V battery connected with a slide-switch too

PROBLEM AND HOW WE FIXED IT

In our prototype, the ultrasonic sensor was always on and so was the LED. The Arduino Nano was directly connected to a battery which gave it a constant supply because of which it was always.

We couldn't keep the SD-CARD always on so we decided to add a slide-switch. Like this, if you want to turn your SD-CARD off you can do so just by using the switch.

HOW WE CREATED OUR CIRCUIT

We used Autodesk Tinkercad to make our circuit and check our code. After testing our circuit on Tinkercad it was time to perform it in real life. We used ARDUINO IDE software to upload the code into the Arduino Nano.

Visit our website: https://pramitranjan1106.wixsite.com/sd-card