Thank you to Wu Jun (aka jjjwu on GitHub) for writing in and sharing a guide to capturing Wi-Fi channel state information (CSI) from a GL.iNet GL-MT6000 router, along with the 'Router CSI Toolkit' scripts that go with it. CSI is the per-subcarrier amplitude and phase data that a Wi-Fi receiver measures to equalize the channel. Because it changes as people move through a room, it is often used for experimental Wi-Fi sensing.

The router is based on the MediaTek MT7986 chipset and runs OpenWrt with an existing mt76 driver CSI patch from the ossiemarks OpenWrt fork. A small daemon on the router streams 80 MHz, 256-subcarrier CSI from the 5 GHz radio over UDP to a host PC. There, Python scripts check the capture quality and produce amplitude heatmaps and a simple motion metric. A 10-minute test run produced 57,293 per-chain records at about 95.5 records/s.

While this project doesn't use an SDR, it may interest readers who followed BirriaSDR and Mtk79ICAP, which also patch the mt76 driver to turn MT7921 Wi-Fi dongles into SDRs. The scripts are MIT-licensed and available on GitHub, and the 10-minute dataset is on Zenodo under CC BY 4.0.