Anemometer

I have an anemometer from a La Crosse weather station. I was wondering if it would be possible to use it with an Arduino to monitor the wind speed and direction.

If the anemometer has a pulse output you can use it to trigger an interrupt which will then inrement a counter if rotations. Then number of rotations per second times the distance traveled will give you wind speed.

I have made a 3D printed anemometer based on the above principle using a hall effect sensor and a magnet.

Check how many wires is the connection between the anemometer and the main unit.

I have no experience with a La Crosse weather station, but I have used an anemometer from Davis (6410E) in a project.

The Davis anemometer is pretty simple to use with an Arduino.
Wind speed: a hall sensor will give one pulse per revolution of the speed sensor. An interrupt does increment a counter.
Wind direction: there is a a potentiometer, that will give a variable voltage level. You can evaluate this with an analog input of the Arduino.

Some resources that helped me to start my project (related to Davis anemometer):
http://cactus.io/sensors/weather/anemometer/davis-anemometer
http://cactus.io/hookups/weather/anemometer/davis/hookup-arduino-to-davis-anemometer

http://www.wxforum.net/wxtech/Anemometer-Vane.htm

No idea if the La Crosse anemometer works similar.

Links regarding La Crosse:
https://www.john.geek.nz/2012/08/la-crosse-tx23u-anemometer-communication-protocol/

The following is based on the thought that you will be capturing raw signals from the sensors directly wired to an arduino. If you are processing signals from the wireless connection that is a different approach.

Your anemometer may deliver one click or two clicks per revolution. Several of the La Crosse systems use a pretty common base which delivers two clicks driven by reed switches per revolution so your wind speed calculations need to account for that. Specs are available that can tell you what wind speed is indicated by one click per second so calculation can be worked out from there.

As to the wind vane, again a standard base is often used. These often have eight resistors in sequence around the compass, but not in numerical order. A magnet closes either one or two reed switches connecting one or two resistors at any moment., which allows for identifying 16 wind direction values. The output can be measured on an analog input pin, and the resulting value can be assigned it's wind vector in code. Again, there are specs online that help to identify what resistance values (single and double) relate to each vector.

I have found that these cheap wind vane bases do a great job of identifying the eight primary wind (N, SW) vectors but are not reliable for the intermediate values (NNW etc).

Hello
Thanls for those information.
Do you know if the Davis 6410 anemometer work a power source of 3.3V?
My project works with 3.3V

Cheers

pierrot10:
Do you know if the Davis 6410 anemometer work a power source of 3.3V?
My project works with 3.3V

Yes, Davis 6410 anemometer will work from 3 to 5 Volts.
Datasheet: http://www.ekopower.nl/pdf/6410%20anemometer-eko.pdf