Various Projects Find Hidden SDR Capabilities in ESP32 Microcontrollers

Back in 2025, we posted about ESPARGOS, a phased array of many patch antennas, each connected to an ESP32 WiFi microcontroller. ESPARGOS could be used to determine the direction of arrival for WiFi signals and create a live augmented reality heatmap. Recently, the ESPARGOS team has made an exciting discovery. They found that several ESP32 chips have an undocumented feature that lets the firmware bypass the fixed WiFi and Bluetooth functionality and instead capture raw IQ baseband samples. As a result, several ESP32 models can now be used as an internal SDR covering 2.2–2.7 GHz, plus 4.8–6.0 GHz on the