YF-S201 Water Flow Sensor (1-30L/min) - Hall Effect Pulse Output
YF-S201 Water Flow Sensor
The YF-S201 is a hall-effect water flow sensor that outputs frequency pulses proportional to flow rate. It’s commonly used in liquid measurement projects with microcontrollers like Arduino, ESP8266, and Raspberry Pi. The sensor handles flow rates from 1 to 30 litres per minute with ±3% accuracy.
Key Specifications
| Specification | Value |
|---|---|
| Flow Range | 1 – 30 L/min |
| Output Pulse Rate | 450 pulses/L (F = 7.5 × Q Hz) |
| Operating Voltage | 5 – 24V DC |
| Max Current | ≤15 mA at 5V |
| Max Water Pressure | 1.75 MPa |
| Connection | 1/2" BSP thread |
What You Can Build With This
- Automatic plant watering system
- Water consumption monitor for household
- Flow-controlled coffee dispensing machine
- Leak detection and pipe burst alarm
Compatibility
Designed for use with any 3.3V or 5V microcontroller. Connect the yellow signal wire to a digital input with a 10kΩ pull-up resistor. Works directly with Arduino Uno (5V), ESP32 (3.3V with pull-up to 3.3V), and Raspberry Pi (via GPIO with level-safe pull-up voltage). Supply voltage can be taken from the board’s 5V pin.
Wiring Notes
Red = VCC (5–24V), Black = GND, Yellow = pulse output. Always install the sensor with the flow arrow pointing in the water direction. Use a 1k–10kΩ pull-up resistor from the signal line to your microcontroller’s logic voltage. Avoid exceeding 1.75 MPa pressure to prevent damage.
Why Buy from Compoden
Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.
Is this compatible with Arduino Uno?
Yes, connect VCC to 5V, GND to GND, signal to pin 2 with a 10kΩ pull-up to 5V. Use the pulseIn() function or interrupts to count pulses.
Can I use this with a 3.3V Raspberry Pi?
Yes. Power the sensor with 5V from the Pi’s 5V pin, but pull the signal line to 3.3V using a 10kΩ resistor to a 3.3V source. Then connect to a GPIO pin. The open-collector output is safe for 3.3V logic when pulled up correctly.
What is the minimum flow rate it can detect?
The sensor reliably detects flows from 1 L/min upward. Below 1 L/min, the internal rotor may not spin consistently, and pulse output becomes irregular.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
Ask Soldr above what you can build with this — it knows every Compoden kit this part appears in.
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