[See Updates below for pictures!]
I’ve always loved the concept of game cartridges. Sure, you can fit lots of games on a flash chip, but there’s just something about the feeling of popping in a new game.
Rather than pursue another commercial project, I recently decided to design a soldering kit with my two boys based on Arduboy and dotMG (though much much simpler than the original dotMG, which had a SAMD51 and large color screen). It will essentially be a Pro Micro-based Arduboy clone, but it will have the Pro Micro housed on a swappable “cartridge”. Some benefits of this will be that 1) programming is easy (vs programming a flash chip), as it will be like any other Arduino; and 2) there will be less wear on the program flash than with a flash chip + bootloader combo; and 3) No boot loading time; 4) pure joy and nostalgia.
Currently I’m looking at using one of the nice large 2.42” OLEDs like this one, but we’ll see.
Another thing I’m excited about is that I think I’ll make a couple of styles for the main board: DMG style vertical/traditional, and another GBA horizontal. Both will be compatible with the same cartridge boards.
Both layouts will be accompanied by laser-cut acrylic shells, held on by nylon standoffs and screws.
I’ll also probably put an analog battery indicator on it by hooking the LiPo to a 3.3V zener diode and LED in series. This will make the LED fade as it nears 3.3V, then shut off when it goes under 3.3V and it’s time to recharge.
Not sure about the RGB LEDs yet, but am leaning towards leaving them off for other uses (see next paragraph).
Lastly, for extensibility, I’ll break out unused pins onto a header, a nod to the “EXT” port on the old DMG Would be a nice way to add a crank like https://play.date, or other sensors/extensions.
And, of course, the goal would be for this to be a beginner-level through-hole soldering kit.
Meta: Sorry for the website link. Not trying to self-promote. The company is shut down, and I’m just sharing it for reference as another piece of inspiration for folks. .
Latest KiCad files, gerbers, parts list, and firmware can be found at: https://github.com/menehune23/arduboy-dotmg
I’ll keep this section up to date with the latest pics too (most recent first).
7/18/2021: Finalized the GBA-style design! Will order in a week or so, hopefully. Files added to repo.
Also, just for fun, the original in white…
7/11/2021: I’ve renamed this project to “dotMG” (and “dotMG Advance”) per the poll later in this thread! I updated the PCBs with the logo . I also took the chance to add a label area to the cartridge PCB, so you can mark them with a sharpie or pen.
Project is now located at: https://github.com/menehune23/arduboy-dotmg, though GitHub should redirect from the old project name too (
3/26/2021: Just built the latest iteration. A few minor tweaks and I’m calling this one good. I’m really digging how that screen border came out! And the updates to make carts easier to take out worked out awesome. On to GBA style next…
3/7/2021: Made some tweaks to the game cart and main board, mainly to make changing carts easier. Also, made the screen cutout a bit more stylish (rounded corners and accented bottom-right corner):
2/23/2021: First build is looking great! Will make a few minor tweaks but pretty happy with it for a first run. Note: cart has breakaway tooth to stuff in connector for reverse insertion protection.