The Arduino controlled incubator to control temperature and humidity

Abstract

The incubator with the aid of a tungsten bulb to maintain the temperature and the water and a desiccator to maintain humidity was developed. The aim here is to enhance the ability of maintaining accuracy in temperature and humidity to keep them in desired value with bulb, water, and copper sulfate desiccator. Obtained results show a tolerance of 2% in temperature, and 3% in humidity inside the incubation area for a finite range. Incubators are widely used for hatching the eggs, food preservation, and laboratory purposes. Overall the incubator was made to study the ability to maintain humidity simultaneously with the temperature and also the accuracy of the both factors in relation to the expected output values. There were ways to maintain a temperature with a reduced error percentage but not clear ways exist to maintain the humidity with minimized error. The system is a closed loop one with feedbacks of the outputs time to time to check and reduce the error percentage. The controller is an on-off controller and the system is controlled by Arduino programming board (Arduino Mega – AT Mega 2560). Since the system is a simple on-off controller system the accuracy of the system is not perfect as well as a fuzzy logic controlled system or Proportional-plus-integral- plus-derivative controller system. Anyway the system suits for normal purposes in agriculture, food preservation, and egg hatching where a range of the temperature or humidity is only required. The system uses sensors to sense the temperature and humidity. The use of heat emitted from a bulb in temperature change is studied in this setup. The effect of exposure of water in adding water vapor to a space to increase the humidity, and the effect of copper sulfate desiccator in absorbing the water vapor to decrease the humidity are also studied throughout the research.

Methodology

A wooden box was made and the lower part of the box was separated by a wooden plate. In the separated lower part a water containing basin was fixed under the separation plate. The plate was drilled and an opening was created to make an interface between the face of water and the upper part of the area. The opening was closed by a plastic door and a 5.0 voltage gear motor was fixed with the door in order to control the opening and closing of the door. A tube like structure was created in the upper surface of the wooden plate and 100grams of dehydrated copper sulfate was added inside the tube. The opening of the tube towards the upper area of the incubator was closed by a plastic door and another 5.0 voltage gear motor is fixed with the door in order to control the opening and closing of the door. A 220 voltage, 100 Watts Tungsten bulb is fixed inside the upper part of the incubator which was the incubation area. Two sensors DHT22 humidity sensor, and LM35temperature sensor were fixed in the incubation area in order to measure the humidity, and temperature values. Adequate wirings were made to connect the motors, bulb, and sensors with the control circuit. The control circuit was created using PCB wizard software. A Relay (125VAC, 5VDC), ULN2003A integrated circuit, and L293D motor controller were used to create the circuit. The circuit was connected to an Arduino Mega development board and adequate wiring was made to connect the circuit board with Arduino Mega development board. The Arduino Mega development board was programmed to maintain the system with the desired values of temperature, and humidity.