Circuit Documentation

Summary

This circuit is an alcohol dispenser system that uses an ultrasonic sensor to detect the presence of a hand and activates a water pump to dispense alcohol. The system is controlled by an Arduino UNO microcontroller.

Component List

1. Ultrasonic Sensor

   • Description: Measures distance by using ultrasonic waves.
   • Pins: +VCC, Trigger, Echo, GND

2. Arduino UNO

   • Description: Microcontroller board based on the ATmega328P.
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

3. Resistor

   • Description: Limits the current flow in the circuit.
   • Pins: pin1, pin2
   • Properties:
     • Resistance: 200 Ohms

4. Battery 12V

   • Description: Provides power to the circuit.
   • Pins: +, -

5. NPN-Transistor

   • Description: Acts as a switch to control the water pump.
   • Pins: E, C, B

6. 5V Mini Water Pump

   • Description: Dispenses alcohol when activated.
   • Pins: positive pin, negative pin

Wiring Details

Ultrasonic Sensor

• +VCC: Connected to Arduino UNO 3.3V
• Trigger: Connected to Arduino UNO D5
• Echo: Connected to Arduino UNO D4
• GND: Connected to Arduino UNO GND

Arduino UNO

• 3.3V: Connected to Ultrasonic Sensor +VCC
• D5: Connected to Ultrasonic Sensor Trigger
• D4: Connected to Ultrasonic Sensor Echo
• GND: Connected to Ultrasonic Sensor GND
• D6: Connected to Resistor pin2
• 5V: Connected to NPN-Transistor B

Resistor

• pin1: Connected to NPN-Transistor C
• pin2: Connected to Arduino UNO D6

Battery 12V

• +: Connected to 5V Mini Water Pump positive pin
• -: Connected to NPN-Transistor B and Arduino UNO 5V

NPN-Transistor

• E: Connected to 5V Mini Water Pump negative pin
• C: Connected to Resistor pin1
• B: Connected to Battery 12V - and Arduino UNO 5V

5V Mini Water Pump

• positive pin: Connected to Battery 12V +
• negative pin: Connected to NPN-Transistor E

Documented Code

// ALCOHOL DISPENSER
#define trigger 5
#define echo 4
#define Relay 6

float time = 0, distance = 0;

void setup() {
    Serial.begin(9600);

    pinMode(trigger, OUTPUT);
    pinMode(echo, INPUT);
    pinMode(Relay, OUTPUT);

    delay(200);
}

void loop() {
    measure_distance();
    Serial.println(distance);

    if (distance < 5) {
        digitalWrite(Relay, HIGH);
    } else {
        digitalWrite(Relay, LOW);
    }
    delay(100);
}

void measure_distance() {
    digitalWrite(trigger, LOW);
    delayMicroseconds(2);
    digitalWrite(trigger, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigger, LOW);
    delayMicroseconds(2);
    time = pulseIn(echo, HIGH);

    distance = time * 200 / 20000;
}

This code is for the Arduino UNO microcontroller and is responsible for measuring the distance using the ultrasonic sensor and controlling the water pump based on the measured distance.