Controller Board Options

[AJH4]

I am just getting started and my ultimate goal is to build a Raspberry Pi Arcade as a home project.  However, before I get started, I have an old eMac that I would like to use to test out control layout options and wiring before I buy an old monitor, the wood and the Pi.  Any recommendations for a joystick and button controller board that will USB out to my eMac and, later, will USB to a Raspberry Pi?  The iPAC 2 or 4 looks like it would allow me to start with a basic one stick and one button layout for testing Pac-Man, Donkey Kong, Burger Time, Joust (1P), etc. and still allow me to build it out for spinners and trackballs later.  Am I missing something?  Any recommendations?  There are so many project examples out there that it seems like the options are limitless.  My preference is likely going to be to keep simple small layouts to have a bar top type example.  (The eMac is for proof of concept and since I have one laying around; I know the support for MAME for Macs is not as strong as on Windows, but I think an older version should work.)

[Peabo]

A Raspberry Pi 2 can do 2 joysticks with 6 buttons each off of the GPIO connector.  Buying a RPI 2 would be less than the cost of a Ipac 2, not that there's anything wrong with an Ipac(i own 3)

[AJH4]

So, essentially, I can either spend a bit more now for a board I don't need later in a Raspberry Pi configuration (to play via USB on an eMac G4 now) and won't need it later for a bar top Pi -- but I can use it for a bar top Pi machine if I want -- just not needed.  I don't think that the eMac has target mode video so it does not seem that I can buy just the Pi 2 and use it with the eMac.  I have no desire to mount the very heavy eMac in a bar top as a permanent solution so going straight to a Pi project sounds more economical even if I have to buy a monitor.

[geeteoh]

I went with with the Zero Delay (ZD) USB Arcade Encoder from China. You can get them on eBay for $7.41 with free shipping. I got mine on Amazon for a bit more. You can attach 17 switch contacts to one of these boards (similar to GPIO) . I hooked up two of these encoders to my Raspberry PI 2. No drivers needed (at least with the RetroPie image). The RetroPie image is pretty nice as it has the Emulation Station front end and emulators already set up. I unpacked the image onto the SD card.  Booted it up. Connected to it with winSCP and and transfer the games. I got mine up and running pretty quickly and was experimenting with games and controls right away.

[SavannahLion]

There is an alternative such as using a dedicated controller and that would be to get an AVR 32U4 or compatible board for KADE. You have to do a little work to load the firmware but the long term advantage is that when you move to the RPi you can keep the KADE software or upload new code to do something else such as add support for analog whatever. Be sure to choose a board reccomended by KADE however.

If you're a little braver you can bump up to an ARM board (note RPi uses ARM). There are a variety of boards to choose from and the cost over features is usually far better than AVR.