SparkFun Forums

[jetpr]

I need an idea to read a wind speed and direction

[Pete-O]

How about a little electric motor with one of those little cup-spinner things on it generating a voltage that you can read with an ADC? As for direction...shaft encoder? That would be easy.

Pete

[tmbg]

if you have a shaft encoder, you don't even need the voltage of the motor, because the encoder will give you speed and direction.

In fact, save yourself some work and see if you can find a rotary encoder (like is used for knobs for digital controls, a 'virtual pot') that is non-detent and spins very freely. then just mount your anemometer cups on the shaft. Rotary encoders are very very simple to read with a PIC

[upand_at_them]

Seventy-five dollars gets you a weather station with wind speed, direction, and temperature: http://www.aagelectronica.com/aag/
You just interface it to a PIC or whatever.

Mike

[sparky]

*Really* nice weather station. I wish I would have known about that a few years back before we tried making our ultrasonic anemometer : http://www.sparkfun.com/tutorial/WeBBS/ ... Report.pdf

-Nathan

[kb0thn]

My company makes data loggers for wind site analysis, so we measure a whole lot of wind speed and direction.

I use instruments from Fascinating Electronics, http://www.fascinatingelectronics.com and NRG Systems http://www.nrgsystems.com/. Fascinating's instruments are pretty high quality kits at reasonable prices. NRG's instruments are commercial units and can get to be spending.

Note that Fascinating is currently out of stock of their wind vane kits, however they should have plenty of anemometer kits.

Oh yeah, blatant plug for my company: Check out our wind measurement products at http://www.windmonitor.net/. Source code for our data loggers is available under the GPL license, so that may help you.

-Jim

[zatalian]

how is it possible to measure both speed and direction with only one shaft encoder?

[brennen]

You can tell which direction it's being turned by reading its outputs (depends on the output type as to how direction is interpreted). You measure the time between pulses as the speed of rotation since you know how many bits it takes for one full revolution.

[Philba]

the annemometer only turns one direction. you need an absolute encoder to determine wind direction.