I recently built a remote weatherstation with the core MPU a 8266 running ESPHome. This weatherstation currently pushes the following measurements into my HomeAssistant system via the HA/ESPHome API. Basic direction for this weatherstation came from digiblur.
- Outside temperature using BME280
- Barometric pressure using BME280
- Outside humidity using BME280
- Outside temperature using SHT31-D
- Outside humidity using SHT31-D
- Hacked La Crosse TX58UN tipping bucket raingauge (ebay purchase)
- Hacked La Crosse LTV-W1 Wind Speed Sensor (ebay purchase)
- UV Index using VEML6075 UV
- Ambient Light using MAX44009
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This is a remote unattended weather station. Thus included the following to allow it to be standalone albeit it does connect into my local wifi.
- Wemo D1 mini pro with exernal antenna
- 18650 batter with P4056 based charging circuit connected to 1.5 watt solar panel.
The BME280 has known issues with reliably reporting humity reading.
DHT11 and DHT12 is not trusted in general absolutely.
AHT10 and AHT15 – also not trusted, slow and inaccurate, but maybe better than DHTxx
AM2320 – relatively not that bad (in compare to DHT and AHT)
BME280 and BME680 is always higher temperature and lower humidity (I suspect self-heating) I think those sensors are not for uncalibrated DIY projects)
HDC1080 – wrong (high) humidity
HDC2080 – wrong (high) temperature
SHT2x – OK
SHT3x – OK
SHTC1 and SHTC3 – OK
SHT85 – Perfect
This is why the SHT31-D is included. It also provides a double reference for measuring the temperature. Experience with other commonly using temperature sensors have proven to be much less accurate e.g. DHT22.
As part of this project, a local weewx server was set up alongside Home Assistant on a UNRAID based server using Docker.
Home Assistant automations were created to forward the weather station sensor data to MQTT. A simple generic weewx driver was written to transfer directly from the MQTT topics into the weewx loop packet. By using MQTT topic names that come directly from weewx, the driver is small and simple.
At the time of this writing, ESPHome supports neither the VEML6075 or the MAX44009.
A native ESPHome component was written for the MAX44009 sensor given the difficulties people were having incorporating an external arduino library. This native component has NOT been submitted to ESPHome for merging as it is incomplete. The code to read and calculate the LUX reading came from dantudose github.
Adding the native code for this sensor under the ESPHome directory was not obvious besides submitting a pull request to have the component added to ESHome's github. Turns out you can create a directory under the ESPHome root directory named custom_components. Now copy the max44009 directory under the custom_components directory.
The VEML6075 was added as a custom component in the weatherstation.yaml configuration file. This required writing the UVLightSensor.h and adding the includes and libraries list items in the weatherstation.yaml file.