QuadRF: Raspberry Pi 5-based phased-array radio spots drones and sees WiFi through walls
Original: QuadRF can spot drones and see WiFi through my wall
Why This Matters
Open-source phased-array RF hardware democratizes drone detection and spectrum analysis previously limited to government and enterprise.
QuadRF is an open-source phased-array radio device built on a Raspberry Pi 5 and an FPGA board, capable of detecting WiFi signals through walls and tracking drones in flight. It operates in the 4.9–6 GHz range, includes an AR RF visualizer, and is available on Crowd Supply starting at $499.
QuadRF is a handheld phased-array radio system developed by Martin McCormick, a former SpaceX engineer who worked on Dishy, the original Starlink terminal. Built around a Raspberry Pi 5 and an FPGA board with picosecond-level timing, QuadRF performs advanced signal processing and beamforming across the 4.9–6 GHz frequency range. The device boots into a WiFi hotspot, and users connect via browser to a VNC session running GNU Radio, SDR software, and a custom Augmented Reality RF visualizer that displays signals as color-coded blobs. Jeff Geerling, a tech blogger, tested a prototype with his father—a retired broadcast radio engineer—and confirmed the device successfully identified neighboring 5 GHz WiFi networks and tracked a DJI Mini Pro 4 drone in flight. QuadRF is part of a larger project aimed at building a Moon-scale antenna array capable of Earth-Moon-Earth (EME) experiments, targeting up to 1.15 MW EIRP when multiple modules are chained together. A basic kit is priced at $499 on Crowd Supply, with a Mobile Expansion Pack adding a battery and handheld phone mount. Geerling noted the UI is still rough in early prototype form, citing clunky gain controls as a pain point, but praised overall performance given its Raspberry Pi 5 foundation. The Crowd Supply crowdfunding campaign has reportedly already surpassed its goal.