Eureka! Institutional Repository

This dissertation, refers to both the theoretical and the manufacturing implementation of a system of portable measuring units, transmission and recording of data in the cloud using LoRa technology. Therefore, the elaboration of the work includes the implementation of an IoT system. The protocol stack of LoRa technology includes 4 layers. In Europe LoRa networks use I.S.M. frequency bands, depending on the frequency band in which a LoRa network operates certain limitations are imposed. The shaping technique used is based on the C.S.S. technique, the quantities that determine the distance and the quality of a link are the spread factor, the frequency bandwidth and the coding techniques. The implemented system consists of two devices, the measuring and data transmitting device and the device for receiving and recording the data on a local server and in ThingSpeak. The measuring and data transmitting device consists of an ESP8266 microprocessor, a DHT11 temperature and humidity sensor, an OLED screen and a LoRa transmitter – receiver. The data receiving and logging device includes an ESP8266 microprocessor, an OLED screen and a LoRa transmitter – receiver as well. Also, the data acquisition and recording device, works as a local server simultaneously registering the receiving data on a web page and on ThingSpeak. The maximum distance was link between the two devices under actual conditions for the needs of the thesis was of the order of 3450 meters. In conclusion, it follows that for the existence of a link between the devices, visual contact is necessary, as various physical obstacles and building facilities make it difficult for the devices to communicate. This fact makes the devices ideal for application in a rural environment. Therefore, the purpose of the thesis is achieved, which is the transmission of measurement data at distances of two to three kilometers using LoRa communication.