During the 80s and early 90s, light guns were very popular in the video gaming world, especially with games such as DuckHunt being cultural landmarks, however, their popularity has waned.
Instead, they are now being used in new and novel ways, such as being turned into a wireless phone, as demonstrated by Nick on GitHub.
The original Zapper gun worked by finding a particular pixel pattern that was only displayed momentarily when the trigger was pulled, but by removing the anti-cheat mechanism, it could be turned into an analog light sensor.
As there were no microphones in the original hardware, a laser, wired to a microphone, is then added to the system and pointed back at the gun, allowing audio to be communicated between the phone and the gun via photodiodes.
While this particular phone needs to be pointed in the exact right place to work, it demonstrates the potential uses for old hardware with the addition of some modern changes.
