Perfect for multitasking, one Pokemon X and Y player built a hands-free shiny finder that notifies him when the game encounters a shiny Pokemon.
With a state machine and less than 300 lines of code, one Pokemon X and Y trainer, going by the online handle dekuNukem, has built a way to hunt shinies, Pokemon with rare coloration, while he is away from his 3DS.
Shiny Pokemon are very rare to simply happen upon by chance. Using a newly added mechanism that increases the rate of shiny Pokemon when successfully chain fishing in X and Y, dekuNukem decided manually fishing over and over was a bit tedious. "Why spend stressful hours trying to fish for just a single shiny when you can sit back and watch it do exactly that, at full speed, without fail, and alert you when it's done?"
With that question in mind, the shiny finder was born. He connected a micro controller to a 3DS to automatically fish and reel in Pokemon. The bottom screen of the 3DS has a different set amount of time of blackout around 11,383 milliseconds. The duration of blackout is slightly longer at 12,623 milliseconds when encountering a shiny Pokemon. A light sensor measures the blackout to determine whether the wild Pokemon is a shiny. If it's not, the microcontroller is programmed to press down, right, A to select the run away option, and then the process begins again. If the wild Pokemon is a shiny, a buzzer sounds to notify the user.
To do this, dekuNukem directly soldered wires onto the motherboard, making the 3DS believe someone is physically pushing a button. He recorded one case of the shiny finder in use. That case took 81 chains to find a shiny, but he said in other cases 50 chains were more likely, and as few as 20 chains occurred. Check out the build in action on YouTube. The source code is available on dropbox.