In a YouTube video, Fangzhan Shi introduced Pi-RTCSI, a self-contained Wi-Fi sensing tool designed for Raspberry Pi CM4 and Raspberry Pi 4B. It’s built using the Nexmon framework and makes use of Round Trip Channel State Information (RTCSI) to achieve phase-accurate localization. It comes ready to use as an SD card image, eliminating any need for environment configuration or compilation.
It can take over 5 minutes to boot the first time, but subsequent boots are quick. Every time you start the computer, the system automatically runs the RTCSI responder 0 configuration through an auto start script located in the home directory. The configuration files specify channel settings and MAC addresses, with Channel 165 as the default. Users must verify local regulatory compliance.
The tool exhibits a great deal of sensitivity, being able to detect oscillations of less than 1 centimeter in amplitude. Directional movement detection through frequency shift analysis in spectrograms is possible through dual responder configurations. Every bit of processing occurs locally on the Raspberry Pi, including RTCSI protocol handling, preprocessing, and visualization. This makes external master PCs completely unnecessary.
