Air pollution is a significant global health issue, with the World Health Organization attributing 4.2 million deaths annually to air pollution and 7 million premature deaths from exposure to it. To combat poor air quality, modern IoT technologies allow individuals to monitor their indoor environment using sensors and microcontrollers to build DIY air quality sensors and monitoring systems. This tutorial provides guidance on creating a system using low-cost electronics like the Arduino Uno, various sensors, and a speaker to detect and alert users to harmful air conditions. The project involves setting up the sensors to gather data on air quality, using pySerial and PubNub for data transmission and visualization, and implementing a real-time alert system. Despite the discontinuation of some tools and frameworks like the PubNub Arduino SDK and PubNub EON, alternative methods like pySerial are suggested for effective data handling and visualization.