Homemade Arduboy vs FX-C

First off huge thanks to Seeed Studio for sending the FX-C so I can take a look at it.

Check out the Arduboy here: https://www.amazon.com/dp/B0GMH1F7R3?...

Promotional code(10% off): BGJ7D7QE

Community: https://community.arduboy.com/t/make-...
Quick-start guide: https://www.arduboy.com/quick-start

Additional Resources:
https://cloud.arduboy.com/
https://community.arduboy.com/t/ardub...
https://bateske.github.io/ArduboyWebF...

I recently made a review video of the FX-C but will also reiterate in written form below with a little introduction to the platform for those who might be interested in it:

I'm a long time fan of the Arduboy platform, having been a member of the forums for several years now. I fell in love with the Arduboy when it was first launched as a Kickstarter but I was a poor college student so couldn't back it at the time. Fast forward a number of years and this is as far as I know the third major iteration of the Arduboy (not counting the mini which is more like a development tool imo). 

The original model could only store one game at a time, and to change the game you had to recompile and flash the new game onto the Arduboy using the Arduino IDE. The next model was the Arduboy FX which with massive support from forum members added an SPI flash memory chip and updated the bootloader to support reflashing games on the fly from external memory. The most recent iteration upgrades the original micro USB port to USB C and adds multiplayer support by routing I2C pins through unused pins on the USB connector.

At it's very core the Arduboy is an 8-bit Microchip ATMEGA32U4 microcontroller with 32K of flash, 2K of EEPROM, native USB support and running at 16MHz. The screen is a 1.3" 1-bit monochrome SD1306 SPI OLED display with a 128x64 resolution. The front of the console is clear polycarbonate and the rear is anodized aluminum. The console only has six buttons (four directions and A and B). Most of my homebrew versions upgrade the display to a 1.54" or 2.42" OLED of the same resolution but available in several monochrome colors (however they use the SD1309 controller which is mostly compatible but requires patching games to support the lack of the internal charge pump command that the 1306 uses). All Arduboys have a 1-bit piezo speaker, RGB LED, and 180mAh LIPO battery. 

The FX and FX-C models have an external 16MB SPI flash memory to store hundreds of games which can flash the internal ATMEGA memory at any time. Game saves are stored in the ATMEGA's internal EEPROM, with the caveat that some games will overlap saves so you do have to be a little careful if you don't want to overwrite or corrupt saves. Flashing games to the flashcart (the SPI flash chip) is handled by either Mr. Blinky's python script or now via several online webtools that use Chrome's ability to connect USB serial devices (this one is my favorite: https://www.bloggingadeadhorse.com/cart/CartBuilder.html?file=flashcart-index&list=BigFX).

The FX-C's standout feature imo is routing the I2C pins through the USB C connector. This is intended for multiplayer games by connecting two Arduboys up with a double ended USB C cable, however I'm more excited because this opens the Arduboy up for integrating it into my electronics projects as a controller or display. Through I2C the Arduboy can be made into a universal programmable IR remote, have removable "backpacks" that add bluetooth, wifi, or even mass storage via micro sd cards! There's an entire world opened up now that there's an easy to access data connection directly wired up the the microcontroller inside the Arduboy!

My homebrew clones served to improve on what I felt were a few shortcomings of the official hardware. Namely the original model's lack of swappable games and adding a much larger SD1309 display through my ArduCart Project:  

The idea was to move the processing to a removable cart and the main console would only need power circuitry, display, buttons, speaker and battery. Basically I wanted to take the Arduboy and bring it back to its Gameboy roots by making it a cart based console. After the FX was released the limited game storage was no longer an issue so I added the flash chip to the ArduCart and rebranded it as the ArduPak. 

Another project I had was to turn the Arduboy into a full home console by adding VGA video output along with bluetooth control support. I demo a working prototype but the project never got past the breadboard stage.

Another idea I played around with was to stuff the Arduboy circuitry into a Dreamcast VMU (and subsequently trying to add wireless charging): 

https://hackaday.io/project/163662-arduboy-in-a-dreamcast-vmu

This VMU form factor was interesting, despite having an even smaller 0.91" display, as I added soft power management by using a Maxim Semiconductor MAX16054 on/off controller which ended up working really well and having very low standby current draw. Additionally I hid the ICSP programming header as well as usb for charging and data underneath the top cap which originally covers the VMU link port.

Sadly it sounds like the FX-C may end up being the final iteration of the Arduboy as it is now but there's talk on the forums of a next era of Arduboy device that utilized more powerful hardware, a color screen, wireless, etc. I'm not really sure what the right direction for the Arduboy to head in would be, but I personally feel like something would be lost changing the core essence of simplicity for complexity. Whatever the future might hold though, I'll always have my homebrew Arduboys and the FX-C to enjoy for years to come.