Few things can humiliate a confident man quite like hearing the words "hey dude, your fly is down." No matter how kind the kind the person or discreet their delivery, the simple fact that they noticed your gaffe is enough to induce great shame. There are only two strategies for avoiding that dishonor: sell all your grownup pants and switch to wearing only joggers, or invent an electronic system that notifies you when you fly is down before anyone else can notice. Guy Dupont took the latter option and built this fly sensor.
This does exactly what you think it does: it tells the user if their fly is down. It does so through a smartphone notification (from a service charmingly dubbed "WiFly"). There are, of course, many legitimate reasons for a person's fly to be down, such as when they are using the restroom. For that reason, WiFly will only push a notification if the user's fly remains down for extended period of time. That user can set that variable according to their anticipated needs. We assume that the user can also turn the system off when they intend to remove their pants entirely.
WiFly works using a Hall effect sensor attached to the fly of a pair of Dupont's jeans. We aren't sure if it was intentional or not, but that sensor looks a little bit like a fly (the insect). A permanent magnet glued to the zipper triggers the sensor when Dupont pulls the zipper all the way down. That wakes up an Adafruit Feather ESP32 development board, which then connects to Wi-Fi. The Feather and its 400mAh LiPo battery reside in a pocket and connect to the sensor through wires running inside the pants. When the Feather wakes up, it checks to see if the sensor remains triggered for the specified amount of time. If it does, then it uses Pushover to send a notification to Dupont's Android smartphone.
The current prototype is a bit bulky, but investment and additional development into wearable textile technology could streamline the technology. We wouldn't be surprised if every new pair of pants includes WiFly technology within a few years. That would finally put an end to one of the most embarrassing situations a grown adult can face.