You can’t search for “retro gaming” without hitting a plethora of single board computers attached to all manner of controls, batteries, etc. Often these projects have an emphasis on functionality above all else but [Kite]’s Circuit-Sword is different. The Circuit-Sword is the heart of a RaspberryPi-based retro gaming machine with an enviable level of fit and finish.
Fundamentally the Circuit-Sword is a single board computer built around a Raspberry Pi Compute Module 3. We don’t see many projects which use a Compute Module instead of the full Pi, but here it is a perfect choice allowing [Kite] to useful peripherals without carrying the baggage of those that don’t make sense for a portable handheld (we’re looking at you, Ethernet). The Circuit-Sword adds USB-C to quickly charge an onboard LiPo (rates up to 1.5A available) and the appropriate headers to connect a specific LCD. The Compute Module omits wireless connectivity so [Kite] added an SDIO WiFi/Bluetooth module. And if you look closely, you may notice an external ATMega mediating a familiar looking set of button and switches.
We think those buttons and switches are the most interesting thing going on here, because the whole board is designed to fit into an original GameBoy enclosure. It turns out replacement enclosures are available from China in surprising variety (try searching for “gameboy housing”) as are a variety of parts to facilitate the installation of different screen options and more. One layer deeper in the wiki there are instructions for case mods you may want to perform to make everything work optimally. The number of possible options the user can mod-in are wide. Extra X/Y buttons? Shoulder buttons on the back? Play Station Portable-style slide joysticks? All detailed. For even more examples, try searching the SudoMod forums. For example, here’s a very visual build log by user [DarrylUK].
The case mod instructions are worth a glance even if you have no intent to build a device. There are some clever techniques to facilitate careful alignment of buttons and accurate hole drilling. Predicting their buyers might want a variety of options, [Kite] added reference drill holes in the PCB for the builder to re-drill for mounting buttons or joysticks. To facilitate adding status LEDs externally there is a tiny PCB jig included. There are even instructions for adding a faux game cartridge for the complete look.
If you want to buy one (we certainly do!) [Kite] does group buys periodically. Check out the wiki for links to the right interest form.
At its core the build uses a Raspberry Pi 3, but one that has been shrunk down to the shape of a memory module, known as the Compute Module 3. (We featured the original build by [inches] before, but [Kite] has taken it over since then.) The upgrade frees up precious space in the GameBoy case to fit the custom PCB that was originally built by [Kite], and also eliminates the need to cut up a Raspberry Pi and solder it to the old version of his PCB. The build is very clean, and runs RetroPie like a champ. It has some additional features as well, such as having an HDMI output.
For anyone looking for that retro GameBoy feel but who wants important upgrades like a backlit color screen, or the ability to play PSP games, this might be the build for you. The video below goes into details about how it all fits together. If you’re looking for more of a challenge in your GameBoy hacks, though, there’s an ongoing challenge to build the tiniest GameBoy possible as well.
We see a lot of Raspberry Pi projects on these pages featuring all variants of the little board from Cambridge, but with one notable exception. Surprisingly few of them have featured its industrial embedded cousin, the Raspberry Pi Compute Module. The Pi-on-a-SODIMM form factor is a neat idea, but we are guessing that the high price of the development board relative to that of a Model B or a Pi Zero has pushed most people in our community towards the latter choice.
The Pi 3 Compute Module was teased all the way back in July, and what we knew then is just about what we know now. The new Compute Module is based on the BCM2837 processor – the same as found in the Raspberry Pi 3 – running at 1.2 GHz with 1 gigabyte of RAM. The basic form factor SODIMM form factor remains the same between the old and new Compute Modules, although the new version is 1 mm taller.
The Compute Module 3 comes with four gigabytes of eMMC Flash and sells for $30 on element14 and RS Components. There’s also a cost-reduced version called the Compute Module 3 Light that forgoes the eMMC Flash and instead breaks out those pins to the connector, allowing platform integrators to put an SD card or Flash chip on a daughter (mother?) board. The CM3 Lite version sells for $25. Continue reading “Raspberry Pi Launches Compute Module 3”→