IoT Environmental Monitoring and Control System in a Research Centre

The core of this paper is to present the realization of a communication system between sensors, for the centralized measurement and transmission of data about temperature and humidity in several university laboratories. The project consists of two subsystems. The first one, sensor measurements node, works as a temperature and humidity controller that can be programmed with a keypad. The measured data will be shown on the integrated display; an external control can also be performed using several optocoupled relays. The second subsystem collects the information sent by each node separately, merges and sends it to the online database for further remote processing. The 433 MHz radio communication technologies are used to transmit data from sensor nodes to the hub, Wireless technology is used to transmit information from the hub to the online database and 315MHz radio communication is used to transmit commands from the hub to sensor node individually. Atmel ATmega328 microcontroller is used for the node and Espressif ESP32 is used for the hub. This configuration represents an optimal solution in terms of cost and energy consumption for controlling and collecting data to the server. The Altium Designer application was used to design the PCB and its electrical and thermal parameters are simulated using the Ansys application suite.