admin writes that multiple independent projects have discovered an undocumented feature in ESP32 chips that bypasses standard WiFi and Bluetooth functions to capture raw IQ baseband samples. This allows several ESP32 models to operate as internal SDRs covering 2.2–2.7 GHz, with the ESP32-C5 extending to 4.8–6.0 GHz at up to 80 MS/s. While most implementations are limited to snapshot-based spectrum analysis due to bandwidth constraints, the new ESP32-S31 supports continuous streaming over Gigabit Ethernet. Other projects have leveraged this feature to enable phase-coherent direction finding and a 5.8 GHz FPV video receiver.
- The ESPARGOS team is not implementing phase-coherent transmissions due to misuse concerns.
- An FPGA-based prototype by user h0m3us3r streams data continuously, though it has poor phase noise.
- The C5VRX project utilizes the undocumented IQ stream for a 5.8 GHz FPV video receiver.
- The ESPARGOS team is not implementing phase-coherent transmissions due to misuse concerns.
- An FPGA-based prototype by user h0m3us3r streams data continuously, though it has poor phase noise.
- The C5VRX project utilizes the undocumented IQ stream for a 5.8 GHz FPV video receiver.
