From there, industrial design, electrical engineering, and mechanical engineering moved forward with the hardware prototype; and interaction design, electrical engineering, and the software development team moved forward with app development, prototyping, and user testing.
The engineering team sourced a pressure sensor that is extremely precise — down to +/-0.00023206038 psi — and that also measures air temperature to help compensate for the difference between outdoor temperature and player’s head temperature due to changes in volume based on the ideal gas law.
Validation testing with a simulated, 3D-printed prototype attached to an iPad mini provided valuable feedback about the directional keypad from a group of high school and college coaches.
Insights from this research led to the rejiggering of several features and addition of new ones, including a well to store a small amount of lubricant right in the pump. Precision inflation requires a lubricated needle, but many users either forget or ignore this step – having it handy might encourage people to do it. The needle clicks into an impression designed to hold it in place when the cord is wrapped – and the cord is designed to a specific length to help the user achieve this.