Ventus W266

Hardware - Ventus W266 TESTING



The Plugin for the Ventus W266 is used to connect a Ventus W266 weather station to ESP Easy universe. The Ventus W266 weather station is also sold under the name of RenkForce W205GU.

The weather station is delivered with 2 units and a power supply. The outdoor sensor unit is battery powered by 4 AA type batteries. It is recommended to use lithium type batteries so the power is stable during the freezing winters.

Specifications (outdoor unit):
  • Outdoor temperature

  • Outdoor humidity

  • Wind direction

  • Average wind speed

  • Gust wind speed

  • Cumulative rainfall

  • UV index

  • Cumulative number of lightning strikes

  • Distance of the nearest lightning strike

Specifications (indoor unit):
  • Indoor temperature

  • Indoor humidity

  • Barometric pressure

  • DCF77 clock


Be aware that this plugin is not build by default because it is disabled. The plugin uses quite a lot of resources like ram and ram. Since the hardware used is also something special we, the author and datux, decided to keep the plugin out of the normal builds. If you want to compile ESP Easy with this plugin enabled you can set the following line in your platformio.ini:

env_default = hard_Ventus_W266

The plugin can only read the sensors of the outdoor unit.



If you are not yet prepared to void the warranty have a look at P124_Ventus_W266_RFM69.ino in the playground. The RFM69HCW unit is able to communicate with the outdoor unit using radio, thus you aren’t forced to do any tinkering with the indoor unit.

This device plugin is multi functional and you’ll want to install multiple instances (add the plugin multiple times) of this plugin to get all the different sensor readings. The outdoor unit has up to 9 sensors values and a minimum of 5 sensor types. Most home controllers, like Domoticz, can read multiple values per sensor type. The temperature sensor for instance also reads the humidity and the wind sensor combines two types of windspeed and the direction. You’ll need one instance per sensor type.

The plugin was originally written for use with (and tested on) Domoticz, which did not support custom multi value sensors at the moment (February 2017). This means the lightning detection is send as two instances. In total you could run as many as nine instances of the plugin to get all values.


ESP               Ventus
GPIO (4)   <-->   MOSI
GPIO (12)  <-->   SCLK
GPIO (14)  <-->   nSEL
GPIO (5)   <-->   MISO

5.0V       <-->   VCC (read note below)
GND        <-->   GND

Set up the piggy back ESP unit according to this schematics. We recommend you using a Wemos D1 mini board since these fit nicely.


If your ESP module has it’s own 3v3 regulator you could connect its power input to the optional power pin specified in the image. The supplied power supply however is not powerful enough to supply both the display with the backlight on and an ESP while transmitting. It is safe to exchange the power supply for a USB power supply of 1A (or higher). The display unit is happy and working fine with only the 5 volts. Some adapters supply more then 5 volts, since the original adapter supplied 6 volts this should not be a problem.

Be mindful when you install the ESP unit. Although the space on the right, above the white display, seems to be perfect for placing the ESP, it is very close to the indoor temperature sensor and your readings on the display will be off by approx. +2 degrees because of the heat generated by the ESP. A better position is all the way on the left where a bare ESP-12E fits perfect, just be sure to supply it with 3.3V instead of the 5V from the supply pin in the picture.

When using a bare ESP be sure to apply the necessary ~10K pull-up resistors to CH_PD (CD_EN), GPIO0 and a pull-down to GPIO15 for stable performance and OTA capabilities.


It is not possible to read the indoor sensors using the plugin nor is it in development or planned.


Task settings


To get started you need to add the device plugin and set the instance to Main + Temp/Hygro. This instance contains the core functionality of the plugin and is needed to read the data send by the outdoor sensor unit. This instance is the only one that has the ability to set the GPIO pins used.

  • Device: Name of plugin

  • Name: Name of the task (example name VentusW266)

  • Enable: Should the task be enabled or not


  • Plugin function: Main, Wind, Rain etc…

  • 1st GPIO (5-MOSI): GPIO 4 (D2).

  • 2nd GPIO (6-SCLK): GPIO 12 (D6).

  • 3rd GPIO (7-nSEL): GPIO 14 (D5).

  • 4th GPIO (8-MISO): GPIO 5 (D1).


You must not have more than 1 main plugin function active! It will not work properly if you have more.

Data acquisition

  • Send to controller 1..3: Check which controller (if any) you want to publish to. All or no controller can be used.

  • Interval: How often should the task publish its value (5..15 seconds is normal).

Rules examples

on VentusW266#UV do
 if [VentusW266#UV]>9
   Publish,%sysname%/Alarm,Stay inside today!

Commands available

Where to buy




Link 1

$ = affiliate links which will give us some money to keep this project running, thank you for using those.