Embedded Software

The embedded software has three parts to it.

• outdoor-location-engine
• indoor-location-engine
• homestation

These three firmwares are designed to play harmoniously together to optimize location accuracy and battery life.

Overall Architecture

There are dedicated pages for each of the firmwares and how to configure them, but above is the overall bird-eye view.

To put it simply, there are two ways to respond (report location), one internally from the Tracker PCB (Responder) and externally from the HomeStation. The goal is to use these two responders in a way that minimizes the usage of the device's valuable resource, the Tracker Battery, while still ensuring visibility of the device's location.

Both HomeStation and Tracker PCB advertises BLE advertisement packets and scan for packets at different intervals to communicate visibility to each other.

The HomeStation advertises BLE ADV packets every second which the IndoorLocationEngine scans for every 30s. While the packets are visible the IndoorLocationEngine puts the NRF-9160 in deep sleep and HomeStation reports the location via WiFi.

The IndoorLocationEngine activates the OutdoorLocationEngine along with its periodic reporting when it doesn't see the HomeStation nearby.