Description This sensor sits in line with your water line and contains a pinwheel sensor to measure how much liquid has moved through it. There’s an integrated magnetic hall effect sensor that outputs an electrical pulse with every revolution. The hall effect sensor is sealed from the water pipe and allows the sensor to stay safe and dry. The sensor comes with three wires: red (5-24VDC power), black (ground) and yellow (Hall effect pulse output). By counting the pulses from the output of the sensor, you can easily calculate water flow. Each pulse is approximately 2.25 milliliters. Note this isn’t a precision sensor, and the pulse rate does vary a bit depending on the flow rate, fluid pressure and sensor orientation. It will need careful calibration if better than 10% precision is required. However, its great for basic measurement tasks! We have as example Arduino sketch that can be used to quickly test the sensor, it will calculate the approximate flow of water in liters/hour. The pulse signal is a simple square wave so its quite easy to log and convert into liters per minute using the following formula. Technical Specifications Model: YF-S201 Sensor Type: Hall effect Working Voltage: 5 to 18V DC (min tested working voltage 4.5V) Max current draw: 15mA @ 5V Output Type: 5V TTL Working Flow Rate: 1 to 30 Liters/Minute Working Temperature range: -25 to 80℃ Working Humidity Range: 35%-80% RH Accuracy: ±10% Maximum water pressure: 1.75 MPa Output duty cycle: 50% -10% Output rise time: 0.04us Output fall time: 0.18us Flow rate pulse characteristics: Frequency (Hz) = 7.5 * Flow rate (L/min) Pulses per Liter: 450 Durability: minimum 300,000 cycles Cable length: 15cm Dimensions: 1/2″ nominal pipe connections, 0.78″ outer diameter, 1/2″ of thread Size: 2.5″ x 1.4″ x 1.4″ Weight: ~50gm (including cable connector) Pinouts Black : 0V / Ground Yellow: Pulse / Frequency flow rate output Red : VCC Power 5V ~ 18V Flow rate Equation Pulse frequency (Hz) / 7.5 = flow rate in L/min. Documents and Downloads YF-S201 Flow Sensor Datasheet YF-S201 flow sensor example arduino code Instructable – How to Use Water Flow Sensor – Arduino Tutorial by codebender_cc DIY-Hacking – A nice tutorial of Flow Rate Sensor Interfacing Package Includes 1x Hall Effect Water Flow Sensor 1-30L/min – YF-S201 (Tested QC-OK)
