1.2M views · Feb 14, 2025 · 10:43 · 1 HN recommender · 4 mentions · discussed 2025–2026
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.
Why Hacker News points people here: Recommended as the companion explanation to the Espargos project, showing how phase and time differences localize devices.
“There's an excellent companion video here”HN comment, 2025
“There's an excellent companion video here”
Excellent companion explanation of the ESP32 antenna array project.
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
“All ESPs are calibrated relatively to each other.”
Summarizes how ESP phase and amplitude data enable localisation.
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.
“it uses both time and phase differences to localize based on MAC addresses”
Shows an ESP32 array localizing WiFi devices by phase and time.
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
“with microwaves via phased arrays [2]”
Author cites own video as example of DIY microwave imaging.
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
