Arcade box configuration (2 player) and switch controllers

IlTia

Hello everyone,
sorry about the newbie question but I really didn't found anything on forums:
I'm going to (I must be sure before buy everything) build an "arcade control box", i.e. just a box where I'll install a 2 player set of 12 buttons and 2 sticks. Everything is wired into an USB Interface, that I will connect at the Raspberry, of course via USB. I've 2 questions:

Ok, at the first boot RetroPie will prompt me the wizard where I can set up the Player 1 configuration (I will press button for x, a ecc.. ecc.). But how can I configure player 2 (is on the same USB plugged in raspberry)? Do I need to edit the global .cfg file of retroarch and add player2 buttons? Or what else?
I want to have also the possibility of swhitch controllers, I mean: I want to unplug my arcade box and plug 1 or 2 snes controllers. How can I configure them? And also, if I unplug my snes controllers and I plug again my arcade box, Does the raspberry PI will recognize again it? Or I need to do again the configuration?

Thank you averyone for the help

caver01

@iltia What USB controller are you planning to use? In other words, what are your buttons going to be wired to?

Also, what emulators are you going to use? If you are using Retroarch libretro cores, yeah, you can probably do whatever configuration you need in the /opt/retropie/configs/all/retroarch.cfg file, but if you are like me, you will find that some arcade games need additional attention on a per-game basis either in their own .cfg files next to the roms themselves, or by using in-game mapping (like hitting TAB inside lr-mame2003).

I am not sure about switching controls, but maybe @meleu's RetroPie-joystick-selection script can help facilitate this.

IlTia

@caver01 I'm going to wire 12 buttons and 2 stick into a standard USB interface (it's sold with the buttons), no manifacture is indicated on the board.
I want to do this because the raspberry itself is out of the control box...

I don't know which emulators I'm going to use yet, sure ps1, snes, neogeo etc...

caver01

@iltia hmm. I don’t think there is a standard USB controller. Some are keyboards and some are gamepad controllers. Either will work, but you might try to find out more about what you are getting because it makes a difference how you configure things.

IlTia

This post is deleted!

IlTia

@caver01 I use the usb interface provided here https://www.ultracabs.co.uk/usb-interface--illuminated-button-joystick-set-460-p.asp.

Anyway, if I plug one USB (no matter which board I use), how is possible to configure 2 players configuration?

caver01

@iltia said in Arcade box configuration (2 player) and switch controllers:

@caver01 I use the usb interface provided here https://www.ultracabs.co.uk/usb-interface--illuminated-button-joystick-set-460-p.asp.

Anyway, if I plug one USB (no matter which board I use), how is possible to configure 2 players configuration?

This is why the controller matters. If the controller presents itself as a keyboard to the computer, well, that's the same way MAME was built many many years ago and there is no problem configuring the "keys" used by both Player 1 and Player 2. However, if the controller presents itself as a gamepad device, this gets harder because most systems are going to think of ALL of the controls from that device as being for one player. Yet, some controllers are built to be smarter than that and present as two separate USB devices, so they appear as two different gamepads.

This is why I mention that there really isn't a "standard" answer, and the choices you make affect how you might need to configure things. It is hard to tell from the description of that USB device how it will work. Someone with experience using it will need to comment here, or you will need to reach out to the vendor to find out what brand it is and do some more research.

I may be overly cautious here, but you don't want to be stuck with an interface that does not work as expected.

IlTia

@caver01 Thank you very much for your time. Can you tell me, if you can, which controller can I use that iterface itself as a keyboard?

Thank you

caver01

@iltia I have an older Ultimarc IPAC4 which is the 4-player version of a very popular keyboard interface. Modern versions have firmware that allows you to configure it to behave as a keyboard or as a keyboard depending on your needs. The IPAC4 is probably overkill unless you need a lot of controls (I have a four-player panel). The IPAC2 is a smaller version of the same. Ultimarc has been making these things for a long time, but there are other keyboard controllers out there by other manufacturers that may be cheaper or easier to find. Perhaps someone else will add a comment about their keyboard controller.

Some folks are even getting away with skipping the controller itself, saving the expense, and simply wiring controls directly to GPIO pins. If you go this route, you then need to run software/drivers that translate the GPIO input into virtual keyboard keypresses. There are several solutions for that such as Adafruit's Retrogame, mholgatem's GPIOnext, and the software used by RecallBox whose name slips my mind. Some of these software tools present a virtual keyboard to the computer and some work like virtual gamepads. GPIOnext, for example, has both options and even lets you trigger commands via GPIO.

If I were to build a smaller bartop today for example, I would probably just use GPIO inputs and software to control it. If you do that, you are limited to the number of buttons you can setup, but you can get a way with 2 players, each with a joystick, 6 buttons, Start and Select(coin).

MattyL42

I've just done this with an ipac2.
You can configure player 2 in the retro arch menu (vids on you tube)
When entering the player 2 button key binds ...Check the order compared to player 1. Strong chance it will not be what you think.
Once you have done that you can quickly map your button inputs and save.