SafeSense

Overview

A native Android safety app that fuses accelerometer, GPS, and audio signals to detect falls, collisions, and distress situations, then dispatches emergency alerts, built with an eye toward real-world hardware constraints on the budget devices common across Cameroon.

The Challenge

Off-the-shelf safety apps assume flagship hardware and reliable connectivity. Building reliable fall/collision detection on common Tecno/Infinix-class devices means handling binary proximity sensors, GPS-denied environments, and battery constraints that most tutorials ignore.

The Solution

Implemented a three-phase fall-detection algorithm and a sensor fusion engine correlating accelerometer, proximity, and audio events within a tight time window, plus a shake-gesture SOS trigger and a WorkManager-based heartbeat service (via Hilt DI) that detects if the monitoring service is silently killed. Ran a full internal audit pass against the sensor pipeline, catching and fixing real issues like GPS failures in offline mode and hardcoded proximity thresholds that don't match real device sensor ranges.

Outcome

Core fall-detection and sensor-fusion logic pass internal audit; GPS, proximity, and audio components have since been hardened based on that audit's findings. Actively in development on the project's dev branch.

Stack