GPS/GPX API for bicycle graphics

2025-07-05

GPS/GPX API for bicycle graphics

I developed an application that processes GPX tracks and GPS positions to provide real-time data for broadcast graphics during cycling events.

Overview

The app fetches GPS positions from tracking devices and exposes various API endpoints that can be consumed by graphics systems for live broadcasts. It's designed to work seamlessly with professional broadcast equipment while providing flexible data formats for different use cases.

Key Features

API Endpoints

The application provides real-time data through the following endpoints:

• Distance remaining - Track how far each rider has left to finish
• Time gaps - Calculate time differences between multiple riders
• Distance gaps - Measure distance between riders
• Average speeds - Monitor mean speeds for each device
• Elevation data - Track current elevation per rider
• Slope information - Calculate gradient/slope for each position

Output Formats

Data is available in multiple formats to suit different integration needs:

• JSON - For programmatic integration (default)
• Text - Simple plain text output
• HTML - Customizable display with font, size, and color options

Real-World Implementation

This system was successfully deployed with AVEO for professional cycling broadcasts. Their setup included:

• Haivision - For video transmission
• Captivate - For broadcast graphics generation

To integrate with this workflow, I developed a Haivision connector that fetches GPS data directly from the encoders. Captivate then ingests the JSON data to create dynamic on-screen graphics.

REST API Examples

The app exposes a clean REST API with intuitive endpoints:

• /api/speed/first/mean/50 - Get average speed over last 50 meters
• /api/gap/distance/first/end - Get distance gap between first and last rider
• And many more...

Format can be specified directly in the URL:

• /api/speed/first/mean/50/text - Returns plain text
• /api/speed/first/mean/50/html - Returns HTML with customizable styling

The HTML output is particularly useful for direct integration with OBS Studio or similar broadcasting software.

Cloud Dashboard

Beyond the API, the application includes a comprehensive web dashboard accessible from any device (iPhone, iPad, laptop, etc.). This dashboard provides real-time visualization while the API serves data to broadcast systems.

Interactive Map View

Track GPX routes and live device positions with automatic tracking:

Elevation Profile

Monitor rider positions on the elevation map in real-time:

Device Statistics

View detailed statistics for each tracking device:

Performance Analytics

Analyze comprehensive performance statistics:

Architecture Benefits

The cloud-hosted architecture ensures:

• High availability during live events
• Scalability to handle multiple concurrent broadcasts
• Easy integration with existing broadcast workflows
• Real-time data updates with minimal latency

This solution bridges the gap between GPS tracking hardware and professional broadcast graphics, making it simple to enhance cycling broadcasts with live, accurate data.

We currently ingest GPX and fetch GPS position on Haivision, but it can work with any GPS solution.