01. THE CORE CONCEPT
What will it do?
The AI Goal Sentinel is a portable, smart training system designed for a 1.6-meter soccer goal. It creates an invisible "Time-of-Flight" laser gate across the goal line. When a football crosses this gate, the system instantly detects the shot, calculates the ball's exact velocity (up to 80 km/h), determines the height/zone of entry, and transmits this telemetry wirelessly to a mobile interface.
Who's done what beforehand?
Professional systems like FIFA's Goal-Line Technology exist, but they rely on $10,000+ arrays of high-speed cameras running at 500 FPS. In the maker community, users often try building speed trackers with I2C LiDAR sensors (like the VL53L0X) or standard webcams. However, these fail in sports applications because their response time (20 to 33 ms) is too slow to catch a fast-moving ball, creating "ghost goals".
My approach solves this by abandoning cameras and using 1ms industrial NPN photoelectric sensors. This achieves professional-grade timing precision at a fraction of the cost.
What sources will you use?
My primary sources will be the official hardware datasheets for the E18-D80NK photoelectric sensors and the Seeed Studio XIAO ESP32-C6. For software, I will utilize the Espressif Arduino Core documentation (specifically for handling IRAM_ATTR hardware interrupts) and Python Flask documentation for the local server interface. I will also reference past Fab Academy documentation for optimizing PCB traces for the SRM-20 milling machine.
