// the take
An ESP8266 sketch that detects nearby people by sniffing Wi-Fi probe requests from phones and publishing hits over MQTT. It's a companion project to a SensorsIot YouTube tutorial, aimed at hobbyists building presence detection for home automation or Node-RED dashboards.
Runs on a $3 ESP8266 instead of a camera or PIR sensor, so it's cheap and has no line-of-sight requirement. MQTT output and the included Node-RED flow make it trivial to wire into Home Assistant or any existing automation stack. Passive sniffing means no pairing or app required on the detected device.
Modern iOS and Android devices randomize their MAC address in probe requests by default, which undermines the core detection mechanism for most phones made in the last several years — the README doesn't mention this limitation or any mitigation. ESP8266 is 2.4GHz-only, so devices that only probe on 5GHz are invisible to it. WiFi and MQTT credentials are hardcoded directly in the .ino/.h files rather than pulled from a config file or secrets mechanism, which is a problem if anyone shares their compiled binary or commits their fork. It's a single-sketch hobby project tied to one video tutorial with no apparent ongoing development, so don't expect bug fixes or support for newer ESP variants.
We read the README, the directory tree and a key source file in October 2026. Nobody pays to be listed. How we judge →