The use of FPGAs in the design of wireless sensor networks can improve the processing system performance so as to develop sensor nodes with powerful embedded processor. In fact, FPGA has a super-parallel processing capacity in data processing and its use and configuration is flexible. This allows intensive digital signal processing tasks like Fast Fourier Transforms to be implemented on the sensor node and this can even support intelligent applications and new security algorithms. This paper presents a wireless sensor network system that monitors and visualizes periodically the environment temperature. The proposed system consists of a base station node based on an FPGA DE2-70 and five sensor nodes having the architecture of the System-on-Chip CC2430.