Given the proposed exercise that consists of carrying out the software code and prototype in Arduino in which two sensors of different types and an actuator intervene, the project is developed from the idea of ??generating an air quality detection system linked to another system opening for ventilation depending on it. In addition, the system is equipped with a presence detector that makes the actuator  to come into operation only when necessary, thus reducing the amount of energy required to operate and preventing it from continuously evaluating. Once in operation, it will also have two light signals as indicators of the state of it.

The objective is to design a suitable system for both residential and industrial spaces in which different types of harmful gases for health may appear. The system  is designed with  an extra ventilation system independent of the general systems that would only come into operation with the presence of people in the room and that would function independent of the general ventilation system.

The circuit carried out works depending on the information received by the two sensors used, on tone hand the circuit comes into operation when the distance sensor detects a person at less than a certain distance, once activated the air quality sensor begins to evaluate the air quality of the room by indicating by means of two LEDs, one red and the other green if it is good or bad quality, if it is bad quality the red LED lights up as an indicator and the servomotor is activated by turning 180 degrees to open of the ventilation system, on the contrary, if it detects that the air quality is optimal, the green led is activated and the servomotor , if previously was activated, is activated again, restarting the movement but in the opposite direction to close the ventilation system.