Project Hub /Security Surveillance & Defense/RFID / NFC Access Systems/DIY Automatic Liquid Dispenser using Arduino and RFID

Intermediate

ARDUINO

Project Specific

3 – 6 Hours

Partial Kit

DIY Automatic Liquid Dispenser using Arduino and RFID

This project implements an RFID-based automatic liquid dispenser using an Arduino Uno to accurately measure and dispense predefined quantities of liquids like water or fuel.

Originally published on ElectronicsForU

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Arduino UNO R3 Board (Compatible) – ATmega328P Microcontroller with USB Cable Rs. 999.00
RFID Reader/Writer RC522 SPI S50 with RFID Card and Tag Rs. 190.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
5V 1 Channel Relay Module Rs. 87.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: Microcontroller IC (DIP) / Chip
Water Pump / Valve
LED Bulb / Lamp / AC Load
Solenoid / Electric Lock
24V DC

Browse all components

How It Works

The DIY Automatic Liquid Dispenser coordinates identification, control, and actuation tasks using an Arduino Uno as the central processing unit. When a user presents one of the 125kHz RFID tags or cards to the EM-18 RFID reader module, the reader captures the unique identification data and transmits it to the Arduino. The Arduino checks this incoming digital data against pre-programmed authorized credentials. If the scanned tag matches an approved record, the microcontroller initiates the dispensing sequence by activating the 5V DC SPST relays (R1 and R2). Because these relays act as electrical switches, they safely isolate the low-voltage control circuitry from the higher power requirements of the output actuators. The ULN 2003 IC provides the necessary current amplification and darlington transistor driving capabilities to switch the 24V DC solenoid valve effectively. Simultaneously, the system can regulate the 220V AC water pump to control the liquid flow. Once the predefined dispensing quantity or duration is met, the Arduino drops the control signals to the relays, shutting off both the pump and the solenoid valve to stop the liquid flow immediately.

Why Build This

Prevent water wastage at public gatherings and functions by automating precise liquid distribution.

Eliminate short-fueling fraud and human error at petrol pumps through automated, card-based dispensing limits.

Gain practical undergraduate-level experience integrating microcontroller logic with high-voltage AC and DC electromechanical actuators.

Real-World Application

Preventing water wastage at public gatherings and functions, and eliminating short-fueling fraud at petrol pumps.

Skills You'll Learn

Microcontroller interfacing

RFID data reading

Relay switching control

Inductive load driving with Darlington arrays

High-voltage AC and low-voltage DC power integration

Safety Precautions

Exercise caution when handling 220V AC water pumps and power supplies.

Technology Tags

ARDUINO

RFID

EM-18

RELAY

ULN2003

SOLENOID VALVE

WATER PUMP

AUTOMATION

Frequently Asked Questions

Can I power the 220V AC water pump directly from the Arduino Uno output pins?

No. The Arduino Uno outputs 5V DC at very low currents, which is incapable of driving a 220V AC pump. You must use the intermediate 5V DC relays and proper isolation to safely control AC mains devices.

What is the purpose of the ULN 2003 IC in this circuit?

The ULN 2003 contains Darlington transistor arrays that provide the necessary current amplification to drive inductive loads like relays and the 24V DC solenoid valve safely from the Arduino's digital output pins.

How does the EM-18 RFID reader communicate with the Arduino Uno?

The EM-18 module typically communicates via asynchronous serial communication, sending the unique ID string of the 125kHz tag directly to the Arduino's RX pin when a card is scanned.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

PRJ-00798