unsurv offline: Open source, privacy, compact GNSS receiver with ESP32 and NFC (schematic and PCB, etc.)

unsurv offline is an ESP32-based privacy-friendly, small and lightweight PCB (45mm x 32mm) with a high-quality GNSS receiver, accelerometer and NFC capabilities. unsurv offline uses a combination of onboard functionality and OpenStreetMap (OSM) data to help you collect and analyze location data in a privacy-friendly way. Originally developed to better understand offline video surveillance, this completely open source project helps you find and develop a variety of custom use cases.

To visualize the ever-expanding video surveillance network, the device can generate daily reports of your proximity to surveillance cameras without exposing your location to any third party. It does this by using the camera location database in OSM on the SD card. Watch our demo above to learn more about this use case.

You can easily access your unsurv data using your smartphone (or any NFC Tag 4 enabled reader) and the dynamic NFC tag integrated into the case. The tiny BMA400 accelerometer helps you conserve valuable battery capacity by managing power saving features. It can even be used as an input device with tap and double tap recognition, or as a fitness tracker with pedometer and run/walk detection.