Just before the holidays, we brought you word of the Arduboy Mini — the latest in the line of open source 8-bit handheld gaming systems designed by [Kevin Bates]. He was good enough to send along a prototype version ahead of the system’s Kickstarter campaign, and we came away impressed with the possibilities it offered for customization.
We’ve always been big fans of the Arduboy here at Hackaday. When creator Kevin Bates showed us the original prototype back in 2014, the idea was to use his unique method of mounting components inside routed holes in the PCB to produce an electronic business card that was just 1.6 mm thick. But the Internet quickly took notice of the demos he posted online, and what started as a one-off project led to a wildly successful Kickstarter for a sleek handheld gaming system that used modern components and manufacturing techniques to pay homage to the 8-bit retro systems that came before it.
It’s the sort of hacker success story that we live for around here, but it didn’t end there. After the Kickstarter, the Arduboy community continued to grow, thanks in no small part to Kevin never forgetting the open source principles the product was built on.
Now Kevin is back with the Arduboy Mini, which not only retains everything that made the original a success, but offers some exciting new possibilities. There’s little doubt that he’s got another success on his hands as well as the community’s backing — at the time of this writing, the Kickstarter campaign for the $29 USD Mini has nearly quadrupled its funding goal.
But even still, Kevin offered us a chance to go hands-on with a prototype of the Arduboy Mini so that anyone on the fence can get a third party’s view on the new system. So without further ado, let’s take a look at how this micro machine stacks up to its full-sized counterparts.
Over the years we’ve seen plenty of homebrew handheld game systems that combine an AVR microcontroller, a few buttons, and an small OLED display. Some of them have even been turned into commercial products, such as the Arduboy. They’re simple, cheap, and with the right software, a lot of fun. But being based on an MCU, most of them share the same limitation of only being able to hold a single game at any one time.
With the microcontroller on the cartridge, the only hardware that stays behind on the Game Card is the SSD1306 128×64 OLED display, buttons, and the battery. That means the handheld is effectively non-functional unless a game is slotted in, but that could be said of most early cartridge-based game systems as well. On the other hand, it also opens up the possibility of producing cartridges with more powerful microcontrollers down the line.
We’re big fans of the Arduboy here at Hackaday, but we’ll admit its tiny screen isn’t exactly ideal for long gaming sessions. There are some DIY builds of the open source handheld that use a larger SPI OLED display, though you’re relatively limited on what kind of changes can be made to the hardware before the games start balking. But as [Nick Bild] shows with his Arduboy home console, hacking the core system library opens up a lot of interesting possibilities.
Games written for the Arduboy make use of a common library that handles all the low-level hardware stuff, which includes a display() function to push the graphical data out to an SPI-connected OLED display. What [Nick] has done is re-write that function to instead output to a custom VGA generator running on the TinyFPGA BX. He had to delete support for the Arduboy’s RGB LEDs because he needed the extra pins, but that shouldn’t cause much of a problem in terms of software support.
This does mean that games need to be recompiled against the modified library to work on his hardware, but as the vast majority of Arduboy software is open source anyway, that’s not much of a problem. We particularly like the Super Game Boy style border you get around the display at no extra cost.
At this point the hardware looks less like a console and more like a breadboard filled with jumpers, so we’re interested in seeing this project taken to its logical conclusion. A custom PCB, enclosure, and possibly even support for using the original NES controllers would turn this into proper system worthy of any hacker’s game room. You could even put the games on custom cartridges if you wanted, though a flash chip that holds the system’s entire library would be quite a bit more convenient.
The key to this project is a pair of transparent CrystalFonts OLED displays, just like the ones [Sean Hodgins] recently used to produce his gorgeous volumetric display. In fact, [Kevin] says it was his success with these displays that inspired him to pursue his own project. With some clever PCB design, he came up with some boards that could be manufactured by OSH Park and put together with jewelry box hinges. Small flexible circuits, also from OSH Park, link the boards and allow the frames to fold up when not being worn.
The Arduglasses use the same ATmega32U4 microcontroller as the Arduboy, and with a few basic controls and a small 100 mAh rechargeable battery onboard, they can technically run anything from the open source handheld’s extensive software library. Of course, technically is the operative word here. While the hardware is capable of playing the games, [Kevin] reports that the OLED displays are too close to the wearer’s eyes to actually focus on them. That said the ability to easily create software for these glasses offers plenty of opportunity for memes, as we see in the video below.
For reasons that are probably obvious, [Kevin] considers the Arduglasses an experiment and isn’t looking to turn them into a commercial product or kit. But if there’s interest, he’s willing to put the design files up on GitHub for anyone who wants to add a pair of Arduino glasses to their cyberpunk wardrobe.
Traditionally, a forum full of technical users trying integrate their own hardware into a game system for the purposes of gaining unfettered access to its entire software library was the kind of thing that would keep engineers at Sony and Nintendo up at night. The development and proliferation of so called “mod chips” were an existential threat to companies that made their money selling video games, and as such, sniffing out these console hackers and keeping their findings from going public for as long as possible was a top priority.
But the Arduboy is no traditional game system. Its games are distributed for free, so a chip that allows users to cram hundreds of them onto the handheld at once isn’t some shady attempt to pull a fast one on the developers, it’s a substantial usability improvement over the stock hardware. So when Arduboy creator Kevin Bates found out about the grassroots effort to expand the system’s internal storage on the official forums, he didn’t try to put a stop to it. Instead, he asked how he could help make it a reality for as many Arduboy owners as possible.
Now, a little less than three years after forum member Mr.Blinky posted his initial concept for hanging an external SPI flash chip on the system’s test pads, the official Arduboy FX Mod-Chip has arrived. Whether you go the DIY route and build your own version or buy the ready-to-go module, one thing is for sure: it’s a must-have upgrade for the Arduboy that will completely change how you use the diminutive handheld.
One of the selling points of the Arduboy is how slim [Kevin Bates] was able to get the Arduino-compatible game system, which is perhaps less surprising when you realize that it originally started out as a design for an electronic business card. But compared to the recently unveiled Nano version, it might as well be the old school “brick” Game Boy.
Now to be clear, [Kevin] isn’t looking to put these into official production. Though it does sound like the bare PCBs might be going up for sale in the near future. This was simply an experiment to see how far he could shrink the core Arduboy hardware while still keeping it not only playable but also code-compatible with the full-size version. While “playable” might be a tad subjective in this case, the video after the break clearly demonstrates that it’s fully functional.
Inside the 3D printed case is the same ATmega32U4 that powers the Arduboy, a 64×32 0.49″ OLED display, and a tiny 25 mAh pouch battery. There’s even a miniature piezo speaker for the bleeps and bloops. All of the pinouts have remained the same so existing code can be moved right over, though the screen is now connected over I2C. [Kevin] has released the schematics for the board in keeping with the general open nature of the Arduboy project, though for now he’s decided to hold onto the board files until it’s clear whether or not there’s a commercial future for the Nano.