Jeija
1 HN recommender · recommended in 3 months, 2025–2026
10:43 · 1.2M views · Feb 14, 2025
The creator of ESPARGOS, an ESP32-based antenna array from the University of Stuttgart, explains how it senses phase and amplitude of WiFi signals to localize devices and build a WiFi camera. It demos the Python library and project.
Recommended as the companion explanation to the Espargos project, showing how phase and time differences localize devices.
4 comments from Hacker News
This project uses an array of ESP32s and some clever calibration techniques to do pretty accurate localisation of WiFi signals. There's an excellent companion video here: this video
Author here. I agree with you, "full spectrum" is a generous marketing phrase for what might more accurately be called _extended_ spectrum. People way smarter than me have been able to achieve DIY spatial imaging with x-rays via compressed sensing [1] and with microwaves via phased arrays [2]. Optical wavelengths seem to be at a sweet spot of good angular resolution, varied natural sources, and harmless to humans. [1] [LINK] [2] this video
I was really impressed that a ESP32 Antenna Array Can essentially make a WiFi camera - it uses both time and phase differences to localize based on MAC addresses (which are sent plaintext) this video
As shared elsewhere in this thread: this video TL;DW: the ESP’s WiFi driver provides per incoming packet the carrier’s phase and amplitude. All ESPs are calibrated relatively to each other.