There are a lot of things you can do with a Raspberry Pi, like build an inexpensive streaming PC or, as is also popular, retro gaming. A YouTube user who goes by the name "Wermy" chose the latter route by turning an old Game Boy into an emulator that can play hundreds of games, though he went the extra mile with his mod.
The Cliff Notes version is that Wermy took an original Game Boy, gutted it, and rebuilt it as something awesome using a Raspberry Pi Zero, the least expensive Raspberry Pi model available at just $5.
Though it's cheap, the tiny PC is surprisingly fleshed out, consisting of a Broadcom BCM2835 application processor (1GHz ARM11 core), 512MB of LPDDR2 RAM, microSD card slot, mini-HDMI socket for 1080p output at 60 frames per second, micro USB sockets, an unpopulated 40-ppin GPIO header, and an unpopulated composite video header.
It's also the smallest Raspberry Pi model to date at 65mm x 30mm x 5mm, making it tiny enough to stuff in the battery compartment of a first generation Game Boy, as Wermy did. There was even room left over for a rechargeable battery.
Wermy isn't the first to do something like this, though what makes his unique is a series of mods along the way. He added a 3.5-inch composite display for color gaming, then drilled out a pair of holes to add two more buttons (X and Y) that he plucked from an original NES controller. A tour of the modded Game Boy also reveals an external USB port for connecting a keyboard or mouse (or whatever), a mini HDMI port in place of the contrast scroller, a micro-USB port for charging, and two additional L and R buttons in the back that he made by drilling out the screw posts.
The Raspberry Pi Zero sits inside the battery port, as does the rechargeable 2,000 mAh battery that he bought from Adafruit. He also added Bluetooth support to a spare port, and some buttons attached to the display for adjusting contrast and brightness.
In addition to all that, Wermy took a Game Boy cartridge and modded it into an SD card reader, which he can fill with content and load onto the Game Boy.
"I modified an original Game Boy cartridge to act as an SD card adapter for the Pi, so I can have the same satisfaction of putting a cartridge in and powering it on like you would on a regular Game Boy," Wermy explains.
It's crazy to think that a cartridge that once held a single game can now hold hundreds, and for different systems. In this case, the custom Game Boy Zero is running Emulation Station, which allows Wermy to play games from a variety of systems.