Various Projects Find Hidden SDR Capabilities in ESP32 Microcontrollers

Researchers have discovered undocumented SDR capabilities in ESP32 microcontrollers that allow them to capture raw IQ baseband samples across 2.2–2.7 GHz and 4.8–6.0 GHz frequencies, enabling use as spectrum analyzers and signal direction finders. While most ESP32 models can only export data snapshots due to limited bandwidth, the newer ESP32-S31 can stream continuously over Gigabit Ethernet for full radio demodulation. Multiple independent projects, including ESPARGOS, h0m3us3r, and C5VRX, have simultaneously discovered and implemented these hidden capabilities for phased arrays, general-purpose SDRs, and FPV video receivers.