Internet-of-Things sensors have gained popularity in recent years to increase production, cut costs, and boost worker safety. Sensors are devices that detect and respond to changes in environmental conditions. They see particular circumstances in the physical environment (such as light, heat, sound, distance, pressure, presence or absence of gas/liquid, and so on) and create a signal (typically an electrical signal) to indicate their magnitude. There are many valuable sensors frequently used in IoT systems. A few of them are smoke sensors, proximity sensors, gas sensors, movement sensors, pressure sensors, temperature sensors, infrared sensors, etc.