WH-SP-WS01 Wind speed sensor (anemometer)

Table of Contents

1. Hardware

This is an anemometer for a very popular weather station sold on aliexpress (https://www.aliexpress.com/item/4001089508787.html)


The box is labeled that the anemometer is a wind speed sensor for WH2081 which is I assume the weather station model.


A different label on the back of the box:


It has an RJ-11 connector with a short cable:


2. Calibration

2.1. Aliexpress

The way in which pulses from the anemometer can be converted into wind speed has been documented in one of the aliexpress offers https://www.aliexpress.com/item/4000352147677.html


Wind speed is passive switch quantity, wind speed sensor, turn 1 turns, 2 pulse =2HZ. Formula for wind speed: m/s=wind speed Hz * 0.34

Rainfall is passive switch, rain bucket reverses once = 0.33mm

Wind direction: resistance network, equivalent to stepping potentiometer, the user connected to a 10K pull-up resistance voltage, SCM AD can detect the voltage. The wind direction is marked with NSWE direction.

There is also a connection schematic on the same site:


2.2. Weather Sensor Assembly p/n 80422 (Instructables)

I have also found a weather station build description on Instructables LoRaWAN Automatic Weather Station. There the WH-SP-WS01 aneomometer sensor is referenced as one of the parts and a datasheet is provided for it. Unfortunately, the calibration value presented there is different than the one provided on Aliexpress. The datasheet claims that winspeed of 2.4 km/h generates 1 pulse per second (1 Hz). Unfortunately this is entirely inconsistent with what is reported by Aliexpress offer above. The conclusion is that the anemometer needs to be calibrated properly before any real meawsurements can be taken with it.

3. References

Author: Maciej Grela <enki@fsck.pl>