The application of the new promising technology of wireless sensor networks is relevant for many industries and spheres of activity (industry, transport, utilities, security). But at the same time, a number of problems arise: autonomy, coverage radius, etc., for the solution of which it is necessary to use more expensive hardware. The use of the applied network protocol CoAP (Constrained Application Protocol) allows you to significantly reduce the requirements for the computing power of microcontroller devices, which in turn reduces the cost of the system as a whole. The paper proposes the development of hardware and software of a distributed experimental data collection system based on a wireless sensor network and the CoAP protocol. The hardware and software of the data collection system was developed, which includes a wireless sensor network of the sub-gigahertz range, a CoAP server and a Web server. The topology of the developed sensor network is tree-shaped. The network nodes are implemented on the basis of the MSP430G2553 microcontroller, which is characterized by ultra-low power consumption, and the CC1101 sub-gigahertz receiver/transmitter from Texas Instruments. Server software is developed on the basis of Java technologies. The developed hardware and software makes it possible to solve a wide range of problems of collecting, processing and analyzing experimental data without laying wired communications over a large area. The system can be used to implement the promising concept of IoT (Internet of Things).