MQ-5 Gas Sensor If you want to detect different types of gases, you will need sensors. If you need any

MQ-9 Carbon Monoxide, Methane and LPG Gas Sensor Module This is MQ-9 Carbon Monoxide, Methane, and LPG Gas Sensor Module

DHT22 AM2302 is a digital sensor that allows to obtain temperature and relative humidity readings, it is low cost and