Back in October, we posted that several projects found that ESP32 microcontrollers can capture raw I/Q samples and therefore be used as an SDR. Now Jordan has written in to share his 'ESP-WiFi-Jam-Detector', a standalone, receive-only interference detector built on the ESPARGOS esp-sdr code and a Waveshare ESP32-C5-Touch-LCD-3.5 touchscreen board.

Using the ESP32-C5's own Wi-Fi receiver, the device sweeps 2400 - 2483.5 MHz and 5150 - 5895 MHz at 80 MS/s, with no PC needed. It learns a 60-second baseline of the normal RF background, then raises an alarm on a raised wideband noise floor, persistent narrowband carriers, or swept signals, while flagging pulsed wideband energy as suspect. The touchscreen shows a live spectrum and waterfall, and with an SD card inserted, it logs every state change and saves a waterfall image centered on each alarm, so you can see what happened while you were away.

The firmware is open-source under GPL-3.0, and a prebuilt binary is available on the GitHub releases page. The README notes that the device can only show that the RF environment has changed, not prove intent, and that a running microwave oven will look like interference on 2.4 GHz.

AI Disclaimer: Jordan notes that the firmware was written entirely by Claude Code, with Jordan directing it and testing on the hardware.