Using an Arduino Nano 33 IoT, Jithin Sanal designed a home monitoring system capable of detecting noxious gases with an MQ2 sensor as well as sensing temperature, pressure, humidity, and ambient light via a BME280 sensor and an LDR. All of this is mounted onto a custom PCB that’s powered by a 9V battery, or one could also use a 9-12V adapter if more convenient.

Data is passed on to Ubidots over WiFi, which provides a configurable dashboard for viewing the readings anywhere in the world. The system can also send notifications via SMS, email, or Telegram to let you know if anything is awry.