Precise temperature and humidity monitor + HomeAssistant

Sensor

I came along ScioSense portfolio which also includes high performing RHT sensors, called ENS21x family. With the help from Rui from RandomNerdTutorials I was able to adapt his code and made it workable for ENS212; all libraries are already included in the Arduino library selection.

Btw: there are also air quality and pressure sensor available from ScioSense - I guess, I'll build some more projects..

Webserver

On the site from Rui Santos I found an example for a webserver hosting a gauge for humidity and temperature. This was easy to adjust to my needs so showing the results updated on regular basis

Hardware

Furthermore I found a perfect home for my EPS32-S2 mini carrier board (which is not mandatory for this project) - any ESP8266/ESP32 board does the job, however with less joy of LED, switches or battery.

This can be run via USB-C or from a implemented LiPo battery

I've build a carrier board hosting not only the ESP but also

• RGB LED
• tactile switches
• battery monitoring
• battery charging and protection
• I²C interface and level shifter
• in addition I've added a interface for wireless RxTx modules, e.g. HC-12 433MHz

HomeAssistant

Once we have the data available, why not processing them in HomeAssistant (HASS)? The firmware already delivers the data as a JSON message, which can be picked up and displayed from HASS as new entities .

Simply modify the configuration.yaml as shown below

Obviously you need to adjust the IP address accordingly. After restarting HASS you'll have the entities ready to implement in your dashboard

Housing

Case has been built in Fusion360 and provide a a light transfer tube as well as four buttons to activate the switches

Code

The code is written on Arduino IDE.

Important once you're uploading the code

• board: use the "LOLIN S2 Mini" (included in the esp32 board library provided by Espressif Systems
• as the Code uses SPIFFS for holding the web content, you need a data upload add-on called "ESP32 Sketch Data upload" -> currently only supported in Arduino IDE 1.x

In case you're interested in the KiCad data or the Fusion360 housing, drop me a PM