Smart Cistern Water Saver Kit with Arduino Uno + Ultrasonic
Smart Cistern Water Saver Kit with Arduino Uno & Ultrasonic
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Your toilet cistern wastes up to 2 litres of water on every flush because the fill valve runs until a mechanical float touches a physical stop. This kit lets you build a smart add-on that uses an ultrasonic sensor to precisely measure the water level and cut off the valve early, saving that water with every single flush — without modifying your existing plumbing.
What You'll Build
You'll assemble a compact control module that mounts near or inside your cistern. The HC-SR04 ultrasonic sensor tracks the water refill level in real time, and the relay cuts power to an external solenoid valve the moment the target fill is reached. A 0.96-inch OLED displays total litres saved since installation, and the DS3231 real-time clock logs each flush event with timestamps to a microSD card for long-term monitoring.
What You'll Learn
- How to interface an ultrasonic distance sensor (HC-SR04) with Arduino and convert raw echo time into accurate water level measurements
- Using a 5V relay module to control an external AC or DC water valve safely, including flyback diode protection
- Implementing real-time clock (DS3231) data logging to track flush counts and water savings on a microSD card
- Designing a non-invasive water-saving automation that reduces household consumption without altering the existing toilet mechanism
Kit Contents
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| HC-SR04 Ultrasonic Sensor | 1 |
| 5V Relay Module | 1 |
| 0.96in OLED Display | 1 |
| DS3231 RTC Module | 1 |
| MicroSD Card Module | 1 |
| 1N4007 Diode | 3 |
| 10kΩ Resistor | 5 |
| 400-Point Breadboard | 1 |
| Male-to-Male Jumper Wires | 20 |
| 9V Battery Snap Connector | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
Students working on CBSE Class 11–12 physics or computer science projects, B.Tech ECE/EEE undergraduates prototyping water conservation solutions for Smart India Hackathon, and ATL Tinkering Lab facilitators teaching sensor-based automation. The intermediate difficulty also suits hobbyists who want to make their home more water-efficient without complex plumbing modifications.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the QR code on the box to access the AI companion, which has been trained on this exact wiring diagram, code, and calibration steps. You can also reach us on WhatsApp for a direct response from our build engineers.
Does this kit come with the solenoid valve to cut off water?
The kit includes a 5V relay module that can switch an external solenoid valve (12V DC or 230V AC). The valve itself is not included because cistern inlet sizes vary; you can purchase a compatible valve locally and wire it to the relay output.
Will this work with any toilet cistern?
The ultrasonic sensor mounts on the lid or rim with a small bracket (you can 3D-print or secure with double-sided tape). The kit works with most modern cisterns as long as there is a clear vertical measurement path to the water surface. We provide calibration instructions for different tank heights.
Can I log water savings over months?
Yes, the DS3231 RTC and microSD module track every flush event with timestamps. The firmware logs the fill duration and litres saved per flush, and you can analyse the data on a computer to see daily, weekly, or monthly water conservation.
HC-SR04 monitors cistern fill level. Relay valve closes early to save 2 litres per flush.
What's in this kit
Other projects you can build
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items