[See Updates below for pictures!]
So, I used to run modmatic.io (now shut down), and one of my biggest regrets is that I never got to produce dotMG. It hurts my heart to think about because I loved that project so much.
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. .
Updates
Latest KiCad files, gerbers, parts list, and firmware can be found at: https://github.com/menehune23/arduboy-ce
I’ll keep this section up to date with the latest pics too.
I just ordered the PCBs for the DMG-style one (GBA to come later when I have time) and carts. Looking good so far! We’ll see how it all works out when I can build one. I doesn’t necessarily look like it but these will be black with gold plating and white silkscreen:
Carts have a breakaway tooth to stuff in the the card connector for reverse cart protection.
2/23/2021: First build is looking great! Will make a few minor tweaks but pretty happy with it for a first run.