My family has the occasional opportunity to visit my wife’s and my home town. That is always a joyful time; we are excited to see the grandparents, parents, the rest of the family, as well as our old and dear friends. Unfortunately, during the last couple of years, those visits include certain restlessness – and this is due to air pollution. That is the reason why I have decided to make a small personal contribution to the potential solution of this problem.
Since the air quality measuring is not performed in a robust, reliable, systematic and transparent way, I have decided to tackle that side of the problem – by building air pollution monitoring nodes.
After a couple of years of the uninterrupted operation, I decided to retire the existing home automation and replace it with the new one. Since the technology available to the amateurs today is much more affordable, both when it comes to the simplicity of the use and integration but also the price. It is easy for the enthusiasts to combine the state of the art stuff like WiFi and LoRaWAN communication, open source home automation software, ESP8266, Arduino, …
In this post, I describe the various upgrades I have performed on the system during the course of one year.
For almost a year I was playing with various temperature sensors and Arduino. Initially the plan was do use some cheap DHT11 sensors in order to measure soil moisture. After running number of tests I found this method not so reliable. Then, I put a number of DHT11 sensors in the house in order to measure temperature and humidity. Out of 10 sensors, only 2-3 were detecting correct temperatures. Then I tried DHT11’s bigger brother DHT22. The results were much better.
The idea for this project was simple and already seen in number of different projects around the Internet:
install a wireless node in every room of the house and collect temperature and humidity,
send this data to the central node (using the same (upgraded) central node described in previous posts),
store data in database,
display data (web page, iPhone notifications).
System overview is displayed in the picture below: