Image Image

The WindFlag wind indicator


Support for wind speed on the new OLED display, Holfuy and METAR (Ver 2.0)

Send an email to with the Holfuy station ID you want to monitor and tell them you got a WindFlag and you will get the API password back.

I have done a video if you want to see how you find the Holfuy station ID and use the information in the WindFlag web interface.

Download firmware for WindFlag version 2.1.1

New in version 2.1.1 is support for a hall sensor and auto calibration to north. Don't update to 2.1.1 if you don't have the hardware with the magnet and the hall sensor.

Older WindFlags should use firmware version 2.0.8

You can update the firmware via the "Update firmware" tab in the web interface. Just download the firmware file to your computer first.
Please wait 2 minutes before you reboot your WindFlag after a firmware upgrade via the webinterface.

Swedish METAR codes as an example


What is WindFlag?

WindFlag is an indoor wind indicator that always turns to the correct wind direction. The new version also got an OLED display for wind speed. The product is made out of a 3D-printed box, a microcontroller and a stepper motor that turns the lid of the box to the correct heading.

WindFlag supports different data sources. Holfuy (Holfuy needs a password, but it is free of charge), METAR (airport weather) and the Swedish VIVA stations. The microcontroller connects to the data source via wifi (2.4 GHz) and check the wind every two minutes. (METAR is updated every 30 minutes)

The product is only made in  limited numbers. I do everything myself from 3D-printing, soldering and maintaining the software. Contact me on  facebook for the delivery time. I usually have a few in stock. The version I produce at the moment is the one with the arrow as a wind indicator (like a Windex on a sailboat). It is the best looking unit I have made, and is is much easier for me to produce than the windsock version that I sold before. The price is 70 EUR + shipping (approx 10 EUR)  for the new version with OLED display. Included in the price is: The box with the electronics, the wind indicator and a USB-cable. You need a USB charger which is NOT included. Use an old mobile phone charger or similar.

How to install WindFlag

0. Watch the  installation video . It is the easiest way to install the product.

1. Plug in an USB wall charger and connect the included cable to the box. Place the box in the position you want it on display. Make sure you have wifi coverage in the area.

2. Use your phone or PC and go to WIFI-settings. Connect to the new accesspoint named WindFlag

3. If you don't reach the captive portal directly, start a web browser and go to Scan for your home wifi and connect the unit to your network with your own private wifi password (It needs to be a 2.4Ghz network with WPA2 security. Most wifi networks have this configuration)

4. Go back to wifi settings and make sure your phone is connected to the same wifi. A new accesspoint is created with an IP-adress. DON't CONNECT to this IP, but write the IP-address down.

5. REBOOT the WidFlag by removing the USB wall plug from the socket and put it back in again.

6. Start a web browser and go to where iis the IP-address you wrote down in the previous step. You will reach the WindFlag web interface.

7. Calibrate the flag so you have north wind. Look at the installation video on how to do this with the new version that have a sensor and a magnet.

8. Choose data source and wind unit in the web interface. You need a password for Holfuy, but it is free of charge. Instructions in the web iterface how to obtain one.

Installation video

Follow WindFlag on Facebook

Microcontroller esp8266

The brain of the operation is a small microcontroller with wifi that runs custom Arduino code with the job of collecting wind data from the Internet.

Stepper motor

A small motor with high precision that turns to the correct heading after it gets the data from the microcontroller. Goes to sleep between updates to keep it cold and save energy.

The wind indicator

You can put anything on the lid as a wind indicator. The original version has a swedish wooden flag


WindFlag - It is a breeze