WiFi sensing on ESP32 hardware
A focused walkthrough of using ESP32 and ESP32-S3 for CSI-based AI sensing.
What is ESP32 CSI?
ESP32 CSI is Channel State Information exposed by Espressif's WiFi stack — per-packet, per-subcarrier amplitude and phase data.
Why ESP32 is used for WiFi sensing
ESP32 is cheap, ubiquitous, hacker-friendly, and has well-documented CSI APIs via ESP-IDF.
ESP32 vs ESP32-S3
ESP32-S3 adds vector instructions, more RAM, and AI acceleration — making on-device inference practical.
Beginner hardware setup
Connect one ESP32 to USB, flash CSI firmware, point it at your router on a fixed channel, and start logging.
CSI signal collection
Set the WiFi to a fixed channel, log raw CSI to serial or MQTT, and convert to a structured dataset for training.
Common issues
Mismatched channels, IDF version drift, antenna noise, and overlapping WiFi networks are the top causes of bad CSI.
Best practices
Use a dedicated AP, capture baseline empty-room data, and validate model accuracy against known ground truth.