For his final project in UCLA’s Physics 4AL program, [Timothy Kanarsky] used a NodeMCU to smarten up a carefully dissected NERF football. With the addition to dual MPU6050 digital accelerometers and some math, the ball can calculate things like the distance traveled and angular velocity. With a 9 V alkaline battery and a voltage regulator board along for the ride it seems like a lot of weight to toss around; but of course nobody on the Hackaday payroll has thrown a ball in quite some time, so we’re probably not the best judge of such things.
Even if you’re not particularly interested in refining your throw, there’s a lot of fascinating science going on in this project; complete with fancy-looking equations to make you remember just how poorly you did back in math class.
As [Timothy] explains in the write-up, the math used to find velocity and distance traveled with just two accelerometers is not unlike the sort of dead-reckoning used in intercontinental ballistic missiles (ICBMs). Since we’ve already seen model rockets with their own silos, seems all the pieces are falling into place.
The NodeMCU polls the accelerometers every 5 milliseconds, and displays the data on web page complete with scrolling graphs of acceleration and angular velocity. When the button on the rear of the ball is pressed, the data is instead saved to basic Comma Separated Values (CSV) file that’s served up to clients with a minimal FTP server. We might not know much about sportsball, but we definitely like the idea of a file server we can throw at people.
Interestingly, this isn’t the first time we’ve seen an instrumented football. Back in 2011 it took some pretty elaborate hardware to pull this sort of thing off, and it’s fascinating to see how far the state-of-the-art has progressed.