#6 BOSCH BME680, AQI an Industrial Approach to Air Quality and IoT.
My Take:
I came across Bosch BME680 when I was searching for my EnvoSense project. The idea was promising! an Air Quality Index. I bought couple of those modules and started experimenting.
#5 EnviroSense V2, Indoor Air Quality Monitoring [MISC-6814, Dallas DS18820, and SHARP Dust Sensor].
#4 NRF24, Mesh Network, MQTT and Extending the Range.
The Module
NRF24 is a very cheap 2.4 GHz wireless module. Thanks to its reliability and price point it is very common for applications wanted to stay within ISM and not use regular Wi-Fi.