OpenEnergyMonitor Community

Connecting Anemometer for wind-speed logging?

Has anyone connected a cheap anemometer to log wind-speed / direction into the EmonCMS system? e.g.,

(I’d like to put up a pole and log wind speeds for 12 months, to investigate the feasibility of making a small wind turbine for that location.)

Many thanks

If you live reasonably close to the airport, they might have historical data (“METAR” - MET Actual Report). Or search for “METAR EGCN”.

What output does that device produce (so that it can be logged)?

I tried to look it up, it’s radio output, solar powered, 868.3 MHz but no hint of much else on the German manufacturer’s website. So the problem is one of finding the type of transmission and protocol, and then writing software to decode it. And it only transmits every 7 mins, so you need to be quick!

The manual says 0.3 - 50 m/s with 0.1 m/s resolution, and direction in 16 steps (22½°)

This thread looks helpful for decoding the protocol:

Thanks everyone. I’ve emailed the German manufacturer, but I might just be creating unnecessary work by using closed hardware?

For a small amount extra (£43) Adafruit have a wind speed sensor with analog output, and there is open source code available for monitoring it from an Arduino or Raspberry Pi :smiley:

Actually this £2.49 sensor from Maplin looks to be quite the bargain!

It might not last as long as more expensive models? but I only need it to work for 12 months.

I think that has a magnet and reed switch inside (I’ll try to confirm later), if so, you need pulse counting software and a means of calibrating it.

You might be wrong there, I think that’s the one I have and it’s about 6 years old, having seized up once, and freed by a quick twiddle and the application of a squirt of silicone grease with PTFE sprayed on the top bearing (the cap and cups pull off the shaft).
I can’t confirm the reed switch - it’s raining. But it’s not likely to be much else considering the price and power requirements (2 × AA batteries seem to last about 2 years in the transmitter).

It looks like this is the same common anemometer, and the author provides some python code and a link to a datasheet that has the calibrated speed?

Sorry, bumping an old thread but nothing more recent and the question is the same.

I have a broken weather station (Maplin) and ideally want something simpler (wind speed and direction only) which will send out MQTT over WiFi or low powered radio which I can link into my monitoring system. Needs to have solar power as it’s a tricky location to reach easily.

Could build a kit but would prefer something that just works from the box.

What is broken? If the base station, then you can read the 433 data (assuming it is a 433 MHz version) using rtl_433.

Nah, the unit itself. First was replaced under warranty and the second went the same way after Maplin’s unfortunate demise.

In that you are not getting data from it showing on the base station? You may find that it is still sending the data just the base station has stopped receiving it (happened to me).

There are other weather stations out there and if they are 433 then it is possible the rtl_433 will be able to decode it. It is then straightforward to set up a service on a Pi to send the data to an MQTT Broker.

To give the OP and anyone else reading this thread the “complete picture…”

rtl_433 running on a Software Defined Radio.

e.g. something similar to this: Buy RTL-SDR Dongles (RTL2832U)

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