sudomod

(My apologies if it sounds like I'm wanting everyone to go do research for me, I have done my own but As I said I have no experience with electronic internals.)

I recently saw about the emulator for raspberry pi's called retro pie (I am usually late to everything cool) I instantly wanted to make it in a gameboy shell. But I have little to no experience with any internals of electronic. Also all the guides on youtube are using either a rpi zero or rpi 2 but I would like to use a rpi 3. Also I was planning to be able to unplug built in screen (connected via hdmi) and be able to plug it into a computer monitor or tv. Or even better have it connected some other way and be able to have it show up on built in screen AND whatever external monitor. Lastly I can't seem to find any tutorial on how to make (or modify) a Gamepad pcb because I would like for this project to have the full game cube controls. Once again sorry if I sound picky I haven't been told whats possible and impossible yet.

Thanks for any help or advice you can give me!

First of all, good luck with this build because it’s ambitious and complicated. Even more true if you have no knowledge and experience.

Having both internal and external screen is very difficult, you’ll need an hdmi splitter which will likely not fit inside the case.

Having the ability to switch from internal and external screen is doable however with a bit of code and some case modifications.
The code would switch the config.txt from settings for the internal screen to the external screen. Can be activated by a button combo.
But having internal hdmi screen AND exposed port to have external signal is tricky too because it’s very tight there.

For hdmi screen built, check veteran gamers buid log.

As for a full game cube controller, you’ll need to put inside a teensy or a promicro controller to have access to the analog inputs.

It will need some coding skills to sketch the arduino code.

You can check sota’s arduino code here in the forum as a basis.

Thank You, the double screen is not on my top priorities, my main concern is the controls so thanks you for your response I will make sure to check out what you have suggested.

Since he just deliverd the last batch, he may start a new pre Order round soon. You should look at Kites Circuit sword for the main DMG Gameboy.
You can sign up to his email notification and get an email as soon as the new pre order round starts.

Here´s the thread to the last pre order round:
https://www.sudomod.com/forum/viewtopic.php?f=50&t=6145

While waiting for it you could see what you can do with the Gamecube controller. Or just buy a USB Version of it since this seems to be exactly what you want. So no particular need to build one yourself, except you jus want to do it.