GoKawiilESPARGOS team finds undocumented SDR mode in several ESP32 chips
The ESPARGOS project, known for a WiFi direction-finding antenna array built on ESP32 microcontrollers, discovered an undocumented feature letting firmware bypass fixed WiFi/Bluetooth hardware to capture raw IQ baseband samples. This turns several ESP32 models into software-defined radios covering 2.2–2.7 GHz (plus 4.8–6.0 GHz on the ESP32-C5), with sample rates up to 80 MS/s. The newer ESP32-S31 can stream continuously at 16 MS/s over Gigabit Ethernet, and a browser-based tool called ESP-WebSDR lets users flash the firmware and view a live spectrum waterfall.