HIT Impact Android App: Head Impact Monitoring
Kotlin Android app project for HIT Impact V1 traumatic brain injury sensors
Overview
The HIT Impact V1 is a helmet-mounted sensor designed to detect and measure head impacts during sports activities. When the official companion app became unavailable, I developed this open-source Android application to give athletes, coaches, and parents continued access to critical safety data.
The Problem
Head injuries in sports are a serious concern, particularly in contact sports like football, hockey, and rugby. The HIT Impact V1 sensor provides valuable real-time impact data, but without a functioning companion app, the hardware becomes unusable. When hitrecognition.co.uk stopped hosting the official app, users were left with expensive sensors and no way to access their data.
The Solution
This Android application restores full functionality to the HIT Impact V1 sensor by providing:
- Wireless Bluetooth connectivity
- Real-time impact data monitoring
- User-friendly visualization
- Both simplified and technical data views
- Complete access to sensor capabilities
Features
Wireless Connectivity
The app discovers and pairs with HIT Impact V1 sensors over Bluetooth, establishing a reliable connection for continuous monitoring during practice or competition.
Real-Time Monitoring
Impact data displays instantly as events occur, allowing coaches and trainers to make immediate decisions about athlete safety.
Dual View Modes
- Standard View: Easy-to-read format for quick assessment
- Technical View: Detailed sensor data for in-depth analysis
Sports Safety Focus
Specifically designed for athletic environments where quick access to impact information can inform critical health and safety decisions.
Technical Implementation
Architecture
The app follows Android best practices with a clean architecture:
Activities:
MainActivity.kt- Application entry and navigationScanActivity.kt- Bluetooth device discovery and pairingImpactDataActivity.kt- Impact metrics displayRawDataActivity.kt- Advanced technical data viewer
Communication Layer:
Bluetooth.kt- Device communication protocol implementation- Custom data parsing for HIT Impact sensor format
Tech Stack
- Language: Kotlin (96.5% of codebase)
- Platform: Android 5.0 (API 21) minimum
- Build System: Gradle with Kotlin DSL
- Communication: Bluetooth Classic
- UI: Native Android layouts
Requirements
- Android phone or tablet with Bluetooth
- HIT Impact V1 sensor
- Compatible helmet mounting
Development Philosophy
The project is open-source (MIT license) with the goal of keeping safety equipment functional and accessible. By reverse-engineering the sensor protocol and publishing the implementation, I ensured that athletes could continue using their investment in head impact monitoring technology.
Impact & Usage
This app enables:
- Athletes: Personal awareness of impact exposure
- Coaches: Data-driven substitution decisions
- Parents: Peace of mind with objective safety metrics
- Trainers: Evidence-based injury prevention strategies
Future Development
Potential enhancements include:
- Historical data logging and trends
- Multi-sensor support for team monitoring
- Export capabilities for medical review
- Cloud backup and sharing
- Impact threshold alerts
Challenges
Bluetooth Protocol
Without official documentation, the sensor communication protocol required reverse engineering through packet analysis and testing.
Data Interpretation
Converting raw sensor values into meaningful impact metrics required understanding the accelerometer scaling and calibration.
User Experience
Balancing simplicity for quick field use with detailed technical data for post-activity analysis.
Conclusion
The HIT Impact Android app demonstrates how open-source development can extend the life of valuable safety equipment. When commercial support disappeared, the community stepped in to ensure that critical sports safety technology remained functional and accessible.
Source Code: GitHub