Arcade Cabinet with both Raspberry Pi and Pandora's Box

[pforand]

Hi guys (and gals!)

I have built a full size arcade cabinet with a Raspberry Pi (retro pi) in it. I like it, but now i'm upgrading. I want to have a pandora box in there also, with a KVM to switch between systems.

Here's the detail :
Raspberry Pi 3B+
Pandora's box DX
Sanwa joystick with USB encoder (zero delay thingy)

Problem is : Im having trouble with the Sanwa Joystick with the pandora box. Im not sure if it can work thru USB. I'm thinking i have to use the JAMMA cable, but if I do that : I won't be able to switch between systems with the KVM switch.

Anyone tried using a USB encoder with a pandora box? Any tips?

Thanks! I'll send picture of my setup once its ready 
 

[PL1]

Pandora's box DX
Sanwa joystick with USB encoder (zero delay thingy)

Problem is : Im having trouble with the Sanwa Joystick with the pandora box. Im not sure if it can work thru USB. I'm thinking i have to use the JAMMA cable, but if I do that : I won't be able to switch between systems with the KVM switch.

There are two problems with this plan.

As you pointed out, the first problem is that the ZD encoder is a USB device  but JAMMA devices don't need a USB encoder because the joystick microswitches connect to the JAMMA harness and the JAMMA PCB functions as the encoder.

With most encoders, you can get around this by using blocking diodes and wiring the JAMMA harness input to the microswitch in parallel with the encoder input. (see #2 below)

The second problem is that the ZD operates very differently than most modern electronic devices.

JAMMA boards, most encoders, and most modern electronic devices are "active low" devices.  When you apply ground (logic low) to an "active low" input, it triggers the output.
                    Switch
    Ground ____/____ Input

ZD encoders are "active high" devices.  When you apply 5v (logic high) to an "active high" input, it triggers the output.
             Switch
    5v ____/____ Input

There's a way to work around this using a DPDT relay for each button, but that approach is needlessly complicated and expensive compared to this approach:

1. Only apply power to one system at a time, otherwise you might accidently end up in one system's config menu while you're using the other system.

2. Replace the ZDs with an "active low" encoder(s). (IPac, Arduino, etc.)
- Daisy-chain the RasPi encoder ground, JAMMA ground, and all of the button grounds.
- Connect the JAMMA and Encoder inputs as shown below.
-- Band end (-) of both diodes on the NO terminal of the switch.
-- Ground on the COM terminal of the switch.
-- The diodes might not be needed, but they are a cheap insurance policy that will prevent 5v from one system's inputs back-feeding into the other system.

                  Switch  ____ - diode + ___ JAMMA Input
    Ground ___/___|
                             |___  - diode + ___ Encoder Input

Related thread: http://forum.arcadecontrols.com/index.php/topic,163113.0.html


Scott
P.S.  The wiring pinout for the PB is often referred to as "CHAMMA" (Chinese JAMMA) -- 4 pins near #25 are inputs instead of the grounds that you would find in a true JAMMA harness.

[Mike A]

We should examine why you even want to do this. The Pi will play everything the Pandora's Box does and more.

I am curious why you think that is an upgrade. Usually people go the other way.

You would have to get huge benefits from running both systems to justify all of the additional complications.

[Jimbo]

I agree with Mike.  I don't understand the reasoning.  I've tried a pandoras box in the past and it was shockingly bad.  What does it do that your Pi can't?

Now if you said you wanted to put a Mister in there, or a couple of jamma boards with a switcher, I'd say that's a more worthy upgrade.

[pforand]

PL1 --> thanks! I'll look into it. I'm more of a software guy than a hardware, i'm trying to stay away from soldering. But your solution is great : i've taken notes.

Mike and Jimbo --> Well, the pandora box DX is running a few games in the high end that the pi can't. Maybe the 4th Pi is better? Or maybe if I wanted to overclock my pi.. but i'll pass. The Mister looks nice! I'll read up on that.

But you guys are right, it's not the upgrade i was looking for. I'm also looking at a small pc with coin ops to go with the pi. Or that Mister board.

[PL1]

i'm trying to stay away from soldering.

If your soldering skills are really bad, you can use euro-style terminal strips instead.




Scott

[Mike A]

Embrace soldering.
It is really easy.
People are afraid of it for no good reason.
It is a skill that is immensely useful in this hobby and will break down barriers for you.

I am not a hardware or software guy.

I went into college Pre-med. I was going to be a psychiatrist before I decided to go into the family wholesale business full time.

I had zero background in this electronics stuff. I bought my first soldering iron when I was in my thirties.

It is never too late to learn new skills.

[Mike A]

Just last night I learned that I can work with a community to get a guy drunk on Twitch in exchange for some kind of points.

We live in exciting and wonderful times.

[pforand]

You guys are right : i have to learn soldering. It will be helpful. I would need to start with a small project that i can scrap to begin. I've looked around, there are plenty of learning video. Now i only need the time

The Mister board looks nice!  If the little lag of emulation truly disappears with this board, I will most likely replace the pandora box with it.

If i wanted to play more modern games with retro looks (shovel knight, catacomb kids, the messanger, cup head, 20xx) could i do a mini pc with some kind os linux distro?
Does anyone have an arcade that plays those kinds of games? what are your build?

p.s. very sorry for my broken english... not my first language

[keilmillerjr]

Sinking vs Sourcing digital inputs.

Look up specs Pandora's box vs raspberry pi. There is no need to run both. If your raspberry pi is slow as balls, you might want to ditch a prebuilt "retro" image and do it yourself based on raspbian lite or arch.

[Osirus23]

The Mister board looks nice!  If the little lag of emulation truly disappears with this board, I will most likely replace the pandora box with it.

Yeah I plan to get one as my next project. Wife is enrolled in college so I can buy the DE-10 with academic discount.

[pforand]

Here's my build so far.
The cabinet is homemade. I know that the speakers will make some people sick, but I really like the quality. It's robust.
There are leds in the marquee.

Its faaaaarrrr from perfect, but it's all me. Now i want a second system in there, and a beer fridge under it

[thomashenry]

You guys are right : i have to learn soldering. It will be helpful. I would need to start with a small project that i can scrap to begin. I've looked around, there are plenty of learning video. Now i only need the time

The Mister board looks nice!  If the little lag of emulation truly disappears with this board, I will most likely replace the pandora box with it.

If i wanted to play more modern games with retro looks (shovel knight, catacomb kids, the messanger, cup head, 20xx) could i do a mini pc with some kind os linux distro?
Does anyone have an arcade that plays those kinds of games? what are your build?

p.s. very sorry for my broken english... not my first language

Try soldering yes. I've not done any soldering at all apart from maybe some speaker wires. I ordered and made a GERT VGA 666 adapter the other week, and the soldering was much easier than I anticipated. I thought I would make a total mess of it and would need a second kit, in the end it was fine.