ESP32 SDR: from failed 433 MHz experiments to live phone decoding
An ESP32-S3 investigation, updated with live Android decoding and physical tests on 17 October 2026. An ESP32-S3 can expose real radio samples. The question is how far that capability carries toward useful applications. Conceptual illustration. I wanted to turn an ESP32 into something more ambitious than another Wi-Fi gadget: a small radio instrument that could capture a remote-control transmission, send the recording to a phone, decode it and eventually reproduce it. The starting point was the ESPARGOS esp-sdr project , which exposes raw radio samples from hardware already inside supported ESP32 chips. That is an exciting capability. It also raises an easy-to-misunderstand question: if software can ask the chip to tune to a frequency, can the chip actually receive useful information there? We tested that question through firmware changes, controlled radio transmissions, independent receivers and a Flutter phone app. We tried GPS, broadcast FM, 433 MHz remote-control signals, n...