ESPARGOS finds raw radio sampling capability in ESP32 chips

The ESPARGOS team found an undocumented feature in several ESP32 microcontrollers that lets firmware capture raw radio samples rather than use their fixed WiFi and Bluetooth functions, RTL-SDR reported. Supported chips can sample signals across 2.2-2.7 GHz, with an additional 4.8-6.0 GHz range on the ESP32-C5. The discovery also lets ESPARGOS hardware locate arbitrary signals in the 2.4 GHz band instead of only WiFi and Bluetooth transmissions. Most ESP32 models cannot export continuous samples to a computer, limiting that use to spectrum analysis. The ESP32-S31 can stream continuously at up to 16 MS/s through Gigabit Ethernet; compatible software drivers are forthcoming.