An ESP8266 connected to the local Wifi network collects the air temperature, humidity, pressure and particulate matter pollution. Periodically sends the data to the Raspberry Pi through the Rest APIs creating a history in an SQLite database. The user can then monitor the temperature, humidity and pollution trends even outside the local area network by using a mobile app for iOS and Android.
I have also integrated a skill which allows the user to get the air data by asking Alexa directly.

I have developed all the components of the project, both hardware and software:

- Mini weather station
- Firmware
- Rest APIs
- Mobile application
- Alexa skill

The Raspberry Pi hosts the Rest APIs and thanks to a dynamic DNS exposes them publicly which allow the mobile application to work even outside the local area network. I wrote a step by step guide on how to configure the Raspberry.