I've been playing around with emulators for a little while and an idea came to me recently: "What if we built a handheld emulator within the case of an original handheld console?
My initial thoughts were to use a GameBoy Advance, or maybe one of the SP models as the case, and a raspberry Pi as the brain. I soon realised that even if I removed most of the connectors, even the model A would be rather large for this project, and idealy I'd want to use the Pi2 to get the processing power boost.
So I started looking around and I found what looked to be nearly ideal, the O-Droid W, however this went out of production some time ago, so my plans were scuppered.
Hope was not lost however as the very next day I wake up to find the internet going crazy for something called the Pi Zero! About as small as is physically possible, and with a speed boost over the Pi1 to boot, it looks perfect.
So plans started rolling in my head. It would be nice to interface with the devices original screen, but that would be hard, and would lack the desperatly needed hardware acceleration. To get the full use from the GPU, we would need to use HDMI, Composite, or the DSI port. Since the DSI doesn't exist on the Zero, that's out right away. HDMI screens are hard to find at sub 7" sizes and they cost alot too, so those are most likely out. That leaves Composite, or maybe over the GPIO if the speeds can be made good enough.
For input the original buttons should be used, either wired to the Zeros GPIO, or through USB via a Teensy or similar.
An internal battery would probably be a good idea, plus a charging circuit. However due to the very low power consumption of the Zero, powering from 2 AAs might be possible, just like the original device.
The Zero doesn't include audio out, except via HDMI, but aparently the right pins can be accessed from the GPIO, a simple audio circuit could be built on these pins to supply the needed sound.
It would be nice to retain as many of the original features as possible, and I considered making use of the cartridge slot. The most basic way would be to build a ln SDCard reader into a cartrdige, and simply put the games on to SDCards. Alternatively I was wondering if it would be possible to actually play games directly from the cartridges, this is likely not possible, but it would remove the legal grey area of emulation, as no copying would be done. If this can't be done, instead the unit could have a mode where it reads a cartrdige from the slot and dumps it to a file on the Zero, allowing users to copy their games into the device.
I also thought about using a PSP as the base unit for this, it is bigger, has a bigger screen (that I have heard of people interfacing with), and has more buttons. If a PSP is used then a second analogue stick should be added, as this would make the unit able to emulate a much wider variety of consoles. However this would lose some of that retro flair.
Lastly it would be awesome if the unit could have a fall back mode where it boots to a standard desktop, allowing the user to have a nice pocket computer too.
I thought this would be a really cool build idea, it uses a new product, it hacks apart old ones, and it uses many different skills and techniques to bring the whole unit together, I think this would make a really good multi-episode build, that viewers could quite easily copy at home.
Thanks for reading :)
