Week 2: Circuit Assembly and Initial Programming

 During the second week, we started assembling the circuit by connecting the ultrasonic sensor, servo motor, and OLED screen to the Arduino UNO. After setting up the hardware, we wrote the first version of our code. The code allowed the ultrasonic sensor to detect an object, and if the object (a hand) was within the correct range, the servo motor would move to push sanitizer. We also made the OLED display show a simple message, such as “Place your hand”. However, we faced several problems. The ultrasonic sensor sometimes gave incorrect readings, making the servo move at the wrong time. We solved this by adjusting the delay and using filtering techniques. Another problem was that the servo motor was not always responding smoothly, so we modified the code to improve timing. Also, updating the OLED display correctly while keeping the system responsive took some extra effort.

Circuit Explanation for Automatic Hand Sanitizer Dispenser
This circuit diagram represents the automatic hand sanitizer dispenser using an Arduino UNO as the main controller.


And this is the code we have used for the Arduino UNO.
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Servo.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define TRIG_PIN 9
#define ECHO_PIN 10
#define SERVO_PIN 6

Servo servoMotor;

void setup() {
    pinMode(TRIG_PIN, OUTPUT);
    pinMode(ECHO_PIN, INPUT);
    servoMotor.attach(SERVO_PIN);
    servoMotor.write(0);

    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
        while (1);
    }
    
    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(10, 20);
    display.print("Place");
    display.setCursor(10, 40);
    display.print("Your Hand");
    display.display();
}

void loop() {
    long duration;
    int distance;

    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);

    duration = pulseIn(ECHO_PIN, HIGH);
    distance = duration * 0.034 / 2;

    if (distance > 0 && distance <= 10) {
        display.clearDisplay();
        display.setTextSize(2);
        display.setCursor(20, 30);
        display.print("Dropping");
        display.display();

        servoMotor.write(90);
        delay(1000);
        servoMotor.write(0);

        delay(2000);
        display.clearDisplay();
        display.setCursor(10, 20);
        display.print("Place");
        display.setCursor(10, 40);
        display.print("Your Hand");
        display.display();
    }
}



Comments

Post a Comment

Popular posts from this blog

Week 3: Optimization and System Refinement

Image
 In the third week, we focused on improving the performance of our system. First, we refined the code to make sure that the sensor, servo, and OLED screen worked together smoothly. We also adjusted the servo movement so that it pushed the sanitizer in the right amount and at the right speed. To make the system more user-friendly, we added a mini switch, which allowed users to turn the device on and off easily. Another important step was assembling all the components into a stable structure, ensuring the circuit was secure and neatly arranged. We faced some challenges, such as the servo motor moving unexpectedly at times, which we solved by adjusting delays in the code. The OLED screen also needed better optimization to prevent unnecessary flickering. Lastly, arranging all the wires inside the enclosure while keeping the system functional was a bit difficult, but we managed to find a clean and organized solution.
Read more

Week 1: Planning and Design

Image
 In the first week, we planned our project and divided tasks among the three team members. We selected the available components, including the Arduino UNO, ultrasonic sensor (HC-SR04), servo motor (MG995), OLED screen, and jumper wires. We created a simple circuit diagram to connect all the components and started researching how to program the sensor, motor, and display. Our goal was to detect a hand using the sensor, activate the servo to push the sanitizer, and show messages on the OLED screen. One of the challenges we faced was understanding how to properly use the Arduino UNO screen, as none of us had used it before. Another issue was determining the best distance for detecting a hand without false activation. After discussing and testing different ideas, we set a target distance of 10 cm for the sensor to activate the sanitizer. Component: 1- Arduino UNO  Used for: The Arduino UNO is the main microcontroller board that controls all components. It reads data from the ultra...
Read more

Week 4: Final Testing and Presentation

In the final week, we conducted multiple tests to ensure the system worked reliably. We asked different people to use the device and made sure it responded correctly every time. We also adjusted the position of the ultrasonic sensor to prevent accidental activation when people moved near the device. After confirming that everything was working well, we documented all the steps and results to prepare for our final presentation.
Read more