I'm incredibly new to stuff like this, so forgive me if I completely misunderstand stuff. I'm always more on the software side and do a lot of programming, but the only electronics I know are what you get from A Level Physics, which really isn't much at all. I have an RPi3 that I got in August, and have been trying to come up with something I could make with it that I would be able to get plenty of use out of. Quite recently, I had the idea to make a kind of handheld device running retropie (original right? /s). I looked through the list of supported consoles for retropie and picked out the ones I was most interested in, then picked out what controls I'd need to be able to play most of the games. I settled on a Left stick and D-pad, a Right D-pad (intended to be the buttons labelled "C" on an N64 controller), ABXY, and 2 Triggers on each side.
In terms of what I'd want the handheld to look like, I was thinking somewhere between a WiiU and a Switch, so I have a nice large screen in the middle, and had the controls on each side. I was also thinking of doing what the 2DS does and have the body be somewhat wedge shaped, so it's thinner at the base to make it nicer to hold, whilst fitting most of the bulk at the top where I need depth anyway for the triggers. The screen would be around 7" 16:9 so everything's nice and big.
I've done a tonne of research over the last week or so, and I'm figuring out a lot about what components I'll need, how to wire some of them up, and so on. There are still some huge holes in what I know, but I'm hoping that I can learn enough of it as I go.
I've thought through what I know I'll need, and have been watching lots of videos of people building similar devices, and I've brought it down to these things to work on that I'll need someone more experienced to try and explain to me:
- Power: I know the Pi has a micro USB port for power, but I don't know how I'd connect a battery to that. I also don't know how I'd be able to recharge the battery. I've seen these little blue circuits that have a battery connected to them, but I don't know what they are more specifically, and how they are to be used. Would I be able to connect it to the Pi with a micro USB cable, and connect the battery to the square-ish 2-pin connector, then charge from a second micro USB port? Going even further with this, I don't know how much power the whole device will need, and I also don't know what size of battery would be most appropriate (in terms of mAh or Wh or whichever is the most common unit).
- Display: I've found several displays that I could use, and they have a HDMI and a VGA output. I know I can very easily connect the display to the HDMI port on the Pi, but there's another display connector that looks like it wants a ribbon cable of sorts. If I were to find a display that would connect to that, would I be able to set it up so I can plug an external monitor/TV into the HDMI port to play on a larger display? How might I do that?
- Sound: I was originally planning to just use headphones to keep it simple, but how could I get sound working in a more complicated way? As in, I have a volume control on the side of the device that will control both headphone and speaker volume, then when I plug in headphones, it will mute the speaker. Is there another board I'd need for this? Or is this normally managed with simpler circuitry?
- Stick/Pad: Whilst looking at components to get ideas, I found a load of 3DS thumb-pads. While I personally don't really like thumb-sticks, the way the 3DS does it is actually quite comfortable for me. The parts had a little 4-pin ribbon cable thing coming out of it, and I was wondering if it would be possible to have that interface with a Teensy that would be connected to all the buttons for the controller. If that's not possible, then I did find some sticks similar to that on a PSP, and they are described to have a "slidy" feeling which I guess would be the next best thing.
So, anything from suggestions to explanations to resources is very welcome, and hopefully I'll be able to get to the point where I can refine my design to the point at which I can build it. Thanks for any help.
