🚰 Arduino Automatic Water Dispenser (Submersible Pump Version)

An automatic water dispenser built using an Arduino Uno, ultrasonic sensor, and a submersible pump motor. The system automatically dispenses water when a glass or hand is placed under the outlet and stops when it is removed — ensuring hygiene and water conservation.

🧠 Project Overview

This project replaces the traditional manual tap or button-based water dispenser with an automatic, touchless system. When the ultrasonic sensor detects an object (like a glass) within a set distance, the Arduino activates a submersible pump to start dispensing water. Once the object is removed, the pump turns off automatically.
This project was developed by Ciril C Reji as a DIY automation experiment using basic electronic components and Arduino.

⚙️ Components Used

Component	Description
Arduino Uno	Main microcontroller controlling the system
HC-SR04 Ultrasonic Sensor	Detects presence of object (glass/hand)
Submersible Pump Motor (5V/12V)	Pumps water from the container
NPN Transistor / MOSFET (e.g. IRF540 / TIP120)	Switch to drive motor from Arduino
Resistors (1 kΩ, 10 kΩ)	For gate/base control and pull-down
Diode (1N4007)	Flyback protection for motor
Power Supply (5V or 12V DC)	To power the pump and Arduino
Breadboard / Jumper Wires	For circuit connections
Tubing / Water Container	For water storage and flow

🔌 Circuit Diagram

Working principle:

1. The ultrasonic sensor continuously measures the distance to detect a glass.
2. If an object is detected within a threshold (e.g., <10 cm), Arduino outputs a HIGH signal.
3. The transistor or MOSFET switches ON the pump.
4. When the object moves away, the signal goes LOW and pump stops.

💻 Arduino Code

#define TRIG 9
#define ECHO 8
#define PUMP 12
#define LED 13
long duration;
int distance;
int threshold = 10; // Distance in cm
void setup() {
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(PUMP, OUTPUT);
  pinMode(LED, OUTPUT);
  Serial.begin(9600);
}
void loop() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  duration = pulseIn(ECHO, HIGH);
  distance = duration * 0.034 / 2;
  Serial.print("Distance: ");
  Serial.println(distance);
  if (distance < threshold) {
    digitalWrite(PUMP, HIGH);
    digitalWrite(LED, HIGH);
  } else {
    digitalWrite(PUMP, LOW);
    digitalWrite(LED, LOW);
  }
  delay(200);
}

🧩 Working Demo

Power the Arduino with 5V/12V adapter (depending on pump voltage).

Place a glass near the sensor (<10 cm).

Pump turns ON → water flows.

Remove the glass → pump turns OFF.

Troubleshooting

Problem	Cause	Solution
Pump not working	Power supply too weak	Use adapter with higher current (≥1 A)
Sensor not detecting	Incorrect wiring	Check TRIG/ECHO pins and connections
Pump always ON	Wrong transistor orientation / code error	Verify wiring and digital logic
No serial output	Serial monitor not open or wrong baud rate	Set baud to 9600

🚀 Possible Improvements

Add timer cut-off to prevent overflow.

Include LCD display for status messages.

Integrate water level sensor in the container.

Use IR proximity sensor for faster detection.

Make it IoT-enabled with ESP8266 or ESP32.

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📄 License

This project is open-source under the MIT License . Feel free to modify and improve it for personal or educational use.

👨‍💻 Author

Ciril C Reji 📧 cirilcreji@gmail.com

🔗 https://github.com/ciril7