The Water Flow Sensor (YF-S201) is a reliable Hall-effect based liquid flow sensor designed to measure and monitor water consumption in real-time. Built with a durable black plastic housing and a 1/2 inch (G1/2) standard pipe connection, it is easy to install in household, industrial, and IoT applications. The sensor provides a digital pulse output proportional to the water flow rate, making it suitable for projects involving smart water metering, irrigation systems, water dispensers, and filtration units. Its compact design and low power consumption make it ideal for integration with Arduino, ESP32, ESP8266, STM32, and Raspberry Pi microcontrollers.
How It Works
The sensor operates on a turbine and Hall-effect principle. When water flows through the sensor body, it rotates a turbine blade. A Hall-effect sensor detects the turbine’s rotation and generates digital pulses corresponding to the flow rate. By counting these pulses, a microcontroller can calculate:
Instantaneous flow rate (L/min) – based on pulse frequency.
Cumulative volume of water (Liters) – by integrating the number of pulses over time.
This makes the sensor not only suitable for monitoring real-time flow but also for applications where precise water usage tracking is required, such as billing systems, leakage detection, and automated water distribution.
Key Features
Accurate digital pulse output for easy interfacing with microcontrollers.
Wide voltage compatibility (5V – 18V) suitable for embedded systems.
Flow range from 1 L/min to 30 L/min, covering small to medium water flow applications.
Durable plastic body with good resistance to pressure and impact.
Low power consumption, ideal for battery-operated devices.
Compatible with IoT, smart meters, and industrial monitoring systems.
Cost-effective and widely available, making it popular in both DIY and commercial products.
Specifications
| Parameter | Value |
|---|---|
| Model | YF-S201 |
| Operating Voltage | 5 – 18V DC |
| Max Current | ≤ 15 mA (DC 5V) |
| Flow Range | 1 – 30 L/min |
| Water Pressure | ≤ 1.75 MPa |
| Output Type | Digital pulse signal |
| Accuracy | ±3% |
| Thread Size | 1/2 inch (G1/2) |
| Housing Material | Black plastic |
| Connection Type | 3-pin (VCC, GND, Signal) |
| Cable Length | ~15 cm |
| Operating Temp | 0°C – 80°C |
Pin Configuration
| Wire Color | Name | Description |
|---|---|---|
| Red | VCC | Power supply (5–18V) – |
| Black | GND | Ground |
| Yellow | Signal | Digital pulse output |
Applications
Water dispensers & vending machines – monitoring water output.
Smart water meters – for residential and industrial use.
Agricultural irrigation systems – controlling and measuring water usage.
Hydroponics & aquariums – ensuring consistent water flow.
Leakage detection systems – preventing water wastage.
Industrial process control – monitoring liquid flow in manufacturing.
DIY and educational projects – ideal for Arduino and IoT-based experiments.
Installation & Usage Tips
Ensure the sensor is installed vertically for best accuracy.
Always use a filter in front of the sensor to prevent debris from blocking the turbine.
For microcontroller projects, use interrupt pins to read pulses accurately at high flow rates.
Combine with LCD/OLED displays or IoT dashboards for real-time monitoring.
Can be used with libraries like Arduino’s PulseIn() or external flow sensor libraries for easier integration.
