Tracking Footballs with Magnetic Fields

Official NFL footballs are crafted by hand by a company in Chicago called Wilson Sporting Goods. The footballs that are made there typically range from 11 to 11.5 inches in length and weigh anywhere between 14 and 15 ounces on average. Originally, animal bladders lined the outside, occasionally from the inside of a pig, giving the traditional American football the long-standing nickname of a “pigskin.” Now a days, they consist of cowhide leather or vulcanized rubber with laces that are stitched to the top adding mass. This causes the oblong spheres to be naturally lopsided. This is fixed by inserting extra weight to the opposite side of the football balancing it out. Knowing this, a clever hacker will realize that the balancing spot is a perfect place to subtly add a motion tracking transmitter like this one. Doing so makes it possible to the track not only the position of the ball on the field, but its precise location in 3D space!

Since each football is unique, variations between one ball to another exist. This means that embedding a circuit into a football only modifies the equipment slightly, which is a good thing because sports fanatics tend to be very opinionated about whether or not technology should influence the game. So long as the transmitter and loop antenna added to the air bladder doesn’t pass that threshold of about an ounce (or so) difference in weight, then the football itself really isn’t affected much.

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Give yourself a sixth sense on the cheap


Hackaday regular [Mikey Sklar] is no stranger to body modifications. He enjoys tweaking his body in ways that help him with day to day tasks, including a ruler tattoo on his arm and an RFID chip embedded in the web of his hand. Lately, he has been toying around with a less invasive means of getting a better feel for magnetic fields in his surroundings.

Turned on to magnetic rings by a friend, he now wears an epoxy-coated rare earth ring every day, changing the way he interacts with the world. He says that besides the obvious ability to tell when he’s near iron-heavy material, he can also feel cell phone calls, as the speaker draws the ring closer while producing sound.

He says that holding the electric cord of his tea kettle gave him the biggest start, making him feel as if he had been electrocuted, minus the actual shock.

While it’s not the most high-tech hack, [Mikey] is quite happy with the “sixth sense” this reasonably price ring has been able to provide – we just might have to try it out ourselves.