SurfSense is an innovative open-source project that integrates smart technology directly into a surfboard fin. Developed by modsetter, this "smart fin" measures various wave characteristics and provides surfers with real-time feedback and post-session analytics. Its fundamental goal is to empower surfers with data-driven insights into their performance, wave dynamics, and overall progression, moving beyond subjective feel to objective measurement. This project represents a significant step towards bringing advanced IoT capabilities to water sports, making performance analysis accessible and actionable for enthusiasts and professionals alike.

The SurfSense system features robust hardware designed to withstand the harsh marine environment while accurately capturing critical data. At its core is an ESP32 microcontroller, chosen for its powerful processing capabilities, integrated Wi-Fi, and Bluetooth Low Energy (BLE) connectivity, crucial for both data transmission and communication. A suite of sophisticated sensors forms the data acquisition core: an Inertial Measurement Unit (IMU) tracks the fin's orientation, acceleration, and rotation. A GPS module precisely logs location, speed, and trajectory. Additionally, a pressure sensor is incorporated to measure depth and infer speed through water. Power is supplied by a rechargeable battery, ensuring extended operation. All these components are intended to be housed within a custom-designed, waterproof fin enclosure, making it a seamless and integrated part of the surfboard.

The firmware, primarily written for the ESP32, orchestrates the entire data collection and processing pipeline. It continuously polls data from all connected sensors at high frequencies, ensuring detailed capture of every movement and environmental factor. Raw sensor data undergoes filtering and processing algorithms to extract meaningful metrics, such as speed, acceleration, turn angles, wave count, and ride duration. This processed data can be stored locally on an SD card or internal flash memory. Crucially, the firmware manages BLE communication, allowing the fin to transmit real-time data streams to a connected mobile device for immediate feedback. It also handles Wi-Fi connectivity, enabling the fin to upload comprehensive session data to a cloud backend once a surfing session is complete or when a Wi-Fi network is available. Power management routines are also embedded to optimize battery life.

A key component of the SurfSense ecosystem is its accompanying mobile application, developed using Flutter. This cross-platform framework ensures the app runs seamlessly on both iOS and Android devices, providing a consistent user experience. The mobile app serves multiple critical functions: it establishes a BLE connection with the smart fin, allowing users to view real-time metrics such as current speed, acceleration, and wave count directly on their smartphone. Beyond real-time display, the app provides an intuitive interface for configuring fin settings, calibrating sensors, and managing data. Post-session, the app becomes a powerful analytical tool, visualizing recorded data through graphs and maps, highlighting key performance indicators, and allowing surfers to review their wave rides, turn patterns, and overall session statistics. It also facilitates the upload of detailed session data to a cloud service, enabling long-term tracking, comparison, and sharing of performance data.

SurfSense offers numerous benefits for surfers of all skill levels. Beginners can gain objective feedback on their technique, while advanced surfers can fine-tune their performance, analyze specific maneuvers, and optimize their equipment choices. Coaches can utilize the data to provide more precise and personalized guidance. The project's open-source nature is a cornerstone of its philosophy, inviting contributions from the global developer and surfing communities. This collaborative approach fosters innovation, encourages customization, and ensures the project remains adaptable and responsive to user needs. While the repository outlines the core components and functionality, the potential for future enhancements is vast, including advanced machine learning for wave prediction, more sophisticated performance metrics, and integration with other smart devices. SurfSense is not just a device; it's a platform for understanding and improving the surfing experience through the power of data.