ESP-SDR: Raw IQ Capture with Espressif's ESP32 Chips
Summary
The ESP-SDR project enables raw IQ capture on Espressif ESP32 chips by bypassing the fixed-function Wi-Fi modem to access baseband samples, turning the ESP32 into a low-cost SDR platform for the 2.4 GHz ISM band and, on certain chips, 5 GHz. It provides a browser-based Web Serial demo, details on hardware architecture (two-bank SRAM ring buffer, 32-bit IQ samples), and capture settings, plus a SoapySDR GNU Radio driver for integration with SDR apps. The work discusses practical limitations like data throughput bottlenecks and outlines potential applications with ESPARGOS hardware, while noting this feature is undocumented and not a security vulnerability, albeit with security considerations around firmware updates and unencrypted transmissions.