The transformation of an old house into a smart home can be time- and money-consuming, especially due to the integration of new sensors and modifications to the existing electrical wiring. However, this problem can be easily and effectively solved by installing wireless node devices in separate areas to enable monitoring and control of the whole building. The aim of this thesis is to develop a multisensor node connected to Wi-Fi network. The result of presented work is an electronic circuit board functioning as a wireless node. The main part is an ESP8266 microcontroller module programmed in C++ language. The node is connected to the central system using the Mqtt protocol. The central part of the system is implemented using program Home Assistant running on Raspberry PI computer. The node features the ability to measure temperature, humidity, movement, light level, and the ability to control a common household 220 V device. In addition to the hardware, the complete software was developed to support a complete node operation and setup procedure. Communication between the user and the node is carried through a user-friendly interface that allows the user to easily control the node’s operation and settings. Lastly, a complete practical case of the node’s integration in the home automation system is presented.