This Pi-Powered Device Creates Virtual Crowds Using Wi-Fi Signals

Linger is a portable device that allows you to hide your Wi-Fi-enabled devices in plain sight by creating a virtual crowd around you. It uses specific wireless signals from everyone that comes nearby, then rebroadcasts their signals infinitely when they leave, making it seem as if they are still there.

Created by artist Jasper van Loenen, Linger is equipped with a Raspberry Pi Zero, a 7-segment LED display, a pair of TL-WN722N Wi-Fi adapters, and a USB hub. As you pass people on the street and their signals are stored in an SQLitedatabase, the gadget’s display will automatically update to show the number of unique individuals in your group.

Linger listens for and stores probe requests coming from Wi-Fi-enabled devices within range into a SQLite database. When these devices leave the area (determined by the time since their last probe request), it will start resending the saved probe requests (with updated sequence numbers), tricking other listeners into thinking the device is still there.

The more devices Linger sees, the larger its collection of saved probe requests will become. This way, a virtual crowd of people will linger and grow around the device.

You can read more about this interesting project on van Loenen’s website, and find its code on GitHub.