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

To visualize the expanding video surveillance network, this device can generate a daily report of your close encounters with surveillance cameras without exposing your location to any 3rd party. It does this by using a database of camera locations from the OSM on the SD card. Please watch our demo above for more information about this use case.

You can access your unsurv data easily using your smartphone (or any NFC Tag 4 capable reader) and the dynamic NFC tag integrated into the case. A tiny BMA400 accelerometer helps you save precious battery capacity by managing power-saving features. It can even be adapted as an input device with tap and double tap recognition or as a fitness tracker with step counter and running/walking detection.

The kit option includes a high quality 3D printed case with enough space to house a 300 mAh single cell LiPo battery, which can be charged via onboard USB. Do you have access to a 3D printer? Great! The case design files are open source, so you can choose the PCB + antenna version and print the case yourself.

Track the data that is tracking you.

unsurv offline is built to help track a variety of data points. You can track the surveillance cameras that have potentially seen you throughout your day. It will also do simple location logging, automated commute tracking, and map WiFi signal strength. This means you could log your daily commute by bike and ensure that nobody except you has the data. You could map WiFi signal strength in your city and create a map of free WiFi access points. If you use vehicles commercially and want to claim tax benefits, you could use unsurv offline to log each trip. Since unsurv offline is open source, you can utilize the source code to come up with your own custom uses.

Here is a short list of the provided use cases you can build upon:

• surveillance tracker: tracks offline surveillance with the help of OpenStreetMap data and creates a daily report showing how much you have been affected

• fitness tracker: counts your steps and distance travelled, can differentiate between standing / walking / running

• location logger: simply logs location, time, average speed

• mapping WiFi strength: location logger with added periodic WiFi strength measuring

All of these will work with the unsurv companion Android app that you’ve seen in the demo and will be added to an Arduino IDE library for ease of use later on. They can also be found on the unsurv GitHub repository.

Why Not Use Location Tracking On Your Phone?

Implementing an always-on location service on a smartphone is possible, but comes with certain drawbacks: it increases power draw and might not be sustainable throughout the day. Even worse, it potentially exposes your location to third parties, taking away from the privacy focus. unsurv offline solves for all of this as a customizable lightweight, portable, low-power board with every feature you need for powerful location tracking.

Features & Specifications

• Ublox cam m8c GNSS receiver (GPS, Galileo, GLONASS, BeiDou)
• ESP32 Pico D4 Microcontroller
• Texas Instruments RF430CL330 dynamic NFC Interface
• Bosch BMA400 accelerometer for power saving features
• MCP73831 single cell Li-Ion battery charger
• Micro SD slot
• 5 ways to access your data:
  • NFC
  • Bluetooth
  • WiFi
  • SD card
  • micro USB

Comparisons

Support & Documentation

All files for unsurv offline are open source and editable with free tools. The PCB has been desinged using KiCad while the case is designed using FreeCAD You can follow development and have a look at the hardware design and software on our GitHub repository. You can also find the codebase for the Android companion app to interact with your device.

• Board schematics & layout
• Software
• Case
• Website

Manufacturing Plan

The unsurv offline design has seen constant improvements from our previous prototypes, which have led to the present design. Except for small changes due to part shortages or adjustments for certification or popular demand, the design will stay very similar to the one you can see. PCB production & assembly will be done by PCBWay a longtime partner for projects on Crowd Supply.

Fulfillment & Logistics

After testing and packaging the first production batch of Pixie Chroma boards, we will send them on to Crowd Supply’s fulfillment partner, Mouser Electronics, who will distribute them to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.

Risks & Challenges

Due to the worldwide chip shortage, this project could be further delayed if factory lead times increase again. We have sourced most of the scarce components to produce a full manufacturing batch and we are researching alternative ICs in case the situation introduces any new challenges.

Interested in This Project?

While the campaign is live we will be releasing a series of tutorials that will walk you through the process of using unsurv offline for various applications. Learn how to improve offline surveillance data on OpenStreetMap or how to autosync your unsurv offline with a rasperry pi. Stay tuned! Meanwhile, please reach out with any questions using the Ask a technical question page, listed in the link below.