The HVAC CLICK board from MikroElektronika is a prototype board based on a gas sensor, an I2C and UART interface, and a SCD41 temperature and humidity sensor. It is designed to provide a comprehensive solution for HVAC (heating, ventilation and air conditioning) applications. The board features a gas sensor, allowing the measurement of temperature, humidity, and air pressure, as well as a set of I2C and UART interface lines allowing for data exchanges with any compatible microcontroller. The microcontroller is responsible for handling the analog signals acquired by the gas sensor. Additionally, it has an onboard SCD41 temperature and humidity sensor, allowing for the detection of various hazardous gases, including CO2, CO, and methane. HVAC CLICK is also compatible with a range of input devices such as a fan, a damper, and even a ceiling fan. It is suitable for integrating into a variety of HVAC systems, ranging from residential and commercial to industrial applications.