This work presents aspects of Wireless Sensor Networks applied to the promotion of precision, intelligent and autonomous agriculture. The irrigation system developed in this work based on Internet of Things (IoT) concepts aims at avoiding waste that occur in traditional watering, whilst increasing energy efficiency in communications. To develop this irrigation system, the Raspberry Pi 4 was used, together with the XBEE – PRO S1 modules of the Institute of Electrical and Electronic Engineering (IEEE) 802.15.4 standard, to test the desired communication ranges. Measurements of soil humidity, atmospheric conditions and appropriate irrigation schedules provide data that is processed by the monitoring system, to carry out intelligent, autonomous, effective, and waste-free irrigation. One considered the Blynk graphical interface platform to create a dashboard that allows the visualization of the humidity and temperature levels. The configuration of the irrigation system involves the use of a mini pump submersible in water, temperature sensor, and a soil humidity sensor connected to an Arduino Uno. These humidity sensor reports provide the humidity and temperature values to the Raspberry Pi. Underlying results prove the advantages of the proposed solution and show that the efficiency of the communication between XBEE nodes is different depending on the distance. It was possible to compare the two modes of operation (Application Programming Interface, API, and Transparent Mode, AT) whilst realizing that the AT mode is easier and economical to use, as it enables direct configurations and basic communications.