## 1 Introduction
It involves the use of various, either collected or real-time, data sources and technologies to make the farming activity more accurate, controlled, and environment friendly [20; 21]. The microclimate in livestock buildings is a set of parameters of the indoor environment--temperature, humidity, speed of air movement, illumination, noise, aeroionization, concentrations of carbon dioxide, ammonia, hydrogen sulfide, and other gases, as well as dust particles and microorganisms. The economic efficiency of industrial livestock farming depends on the conditions for the rational keeping of animals [22], which is largely determined by the optimal microclimate in the premises. No matter what high breeding and generation qualities an animal may have, without creating a favourable microclimate for them, they are not able to maintain health and demonstrate their potential productive abilities, determined by heredity. The influence of microclimate on the animal's body is determined both by the total influence of its various parameters and by individual parameters. Microclimate affects the physiological processes in the body of animals (heat regulation, gas and energy metabolism, respiration, digestion, and blood circulation), as well as productivity, resistance, and health [23; 24; 25; 26; 27]. As a result of an unsatisfactory microclimate, productivity and reproductive capacity decrease [28], and feed costs per unit of production increase [29]. The artificial microclimate must meet the physiological needs of the body, conducive to obtaining maximum productivity and maintaining the health of animals. Environmental impact on air in PLF is examined in [30] where the authors conclude that it can be indirectly reduced using the PLF technologies. Unlike many recent research and industrial developments to control the composition of the air in an office or home environment, temperature and humidity meters are mainly used in animal husbandry to our knowledge. As a result of our experience [31] of working on the national scientific program \"Intelligent Livestock Husbandry\", we concluded that the design of the environmental monitoring device for PLF should have several main characteristics. Such a device should be inexpensive, allow the measurement of several important indicators of the state of the environment, allow easy scalability, and be based on open-source software so that it can be used by farmers without the need for a long learning curve for work with the device. This paper addresses these gaps and proposes a multi-sensor platform that is designed to allow the addition of different modules according to specific needs and avoid the need for code development due to the use of open-source software with means to access, store, and visualize the measured parameters. This article delves into the integration of sensors capable of measuring ammonia, hydrogen sulfide, carbon monoxide, PM2.5, TVOC, temperature, humidity, and pressure. Such a multi-sensor system provides a holistic view, empowering users with the data needed to make informed decisions about their surroundings. This study aims to construct a multi-sensor air quality monitoring system based on open-source tools and low-cost sensors. Section 2 explores the intricacies of each air quality parameter and basic principles of SOLID architecture design. Section 3 examines the components and equipment needed for the multi-sensor system. The discussion is provided in Section 4. Finally, Section 5 concludes the paper.