PAX (People) tracker

The people tracker (PAX) project tracks crowds based on bluetooth and WiFi signals. The project was initially started at the beginning of the Covid pandemic. Device management is handled via the Span dashboard and each sensor is tagged with metadata, including location coordinates.

Hardware and firmware

PAX IP67 enclosure

The sensors uses ESP-WROOM-32D as the MCU and the firmware is implemented in ESP-IDF/FreeRTOS. The main communication is handled by a uBlox SARA N211. The microBUS version of the sensor is a work in progress. The sensor uses a custom PCB mounted in an IP67 enclosure.

The hardware schematics, BOM and firmware are available at


PAX front end

The backend server is implemented in Go and includes an embedded frontend that visualizes the data from the counters. The frontend code is written in Angular. The backend server keeps a local copy of the reports from the sensors and serves aggregated counters for the fronted via a REST API.

The source code for the backend and frontend is available at