Nowadays the smart house is necessarily useful part of home comfort. Many people can't imagine their lives without smart devices. A lot of companies provide solutions in this field, for example, Chinese company Xiaomi has a wide range of smart devices and people express a great interest in making their houses more intelligent. However, it is also expensive and requires a lot of time to design and implement such intelligent systems. In this paper, we want to show an example of a cheap smart house device with temperature sensor based on Arduino controller and compare it with similar temperature sensors. It can help some people to make a choice between commercially available solutions and users' custom designs based on microcontrollers and additional accessories for Arduino or any other smart microcontroller available in the market, that is also tunable for the best performance. This may also prove to be interesting in terms of programming and smart house organization aspects.