Mommy's Best Games, Inc. is an independent game developer founded in 2007. This is a view behind the scenes of our game development and marketing!


Monday, January 29, 2024

Building the Arcade Cabinet, Part 2: Guts and Wires

As I mentioned last week, I studied many blog posts and videos to figure out the best way to go about building my arcade cabinet for Bumpy Grumpy

And I ended up doing one thing I haven't seen others do. 

Since this was a fairly original cabinet design, AND it was my very first cabinet, my plan was to work backwards. Or rather, inside-out!

Yes! I would build it from the inside out, ensuring that I first had the game running perfectly on all the hardware, and only then would I work on the very tough physical cabinet part afterwards. Once I felt confident in the guts and wires I would move on to the expensive wood and glass. 

Control Panel Parts

When you are building your cabinet and the first shipment of buttons and controllers arrive, it feels amazing!

I thought the colored wires were excessive, but it helps when connecting all the buttons to have different colored wires, to help keep things visual and easier to understand!

These are 22 gauge "hook up" wire. You want it pretty thin, but definitely use insulated wire, to connect your buttons.

I've had the idea to build a cabinet for years. And years ago, a standard 4'x8' sheet of 3/4" plywood was only $40. Now it was easily $80! So I was pretty worried about getting into the cabinet part of it, and wasting a bunch of money with mistakes. I had to get it right on the insides first. 

So to start with, I bought all the buttons and controllers I needed. The design for Bumpy Grumpy uses one control stick, and 2 main buttons (one for the Gas to drive, and one for the Brakes to stop). But I also wanted a 1-Player button. And because the original designer Occidental Designs was very forward thinking they offered "left-handed" buttons, which happened on some older machines. So I also needed another Gas and Brakes for the left-hand side. But still just one control stick.

I bought the buttons and control stick from Paradise Arcade shop. The prices and shipping all worked out and pretty good and I would recommend them. I like the simple HAPP buttons. They have a solid construction and feel. Lots of people like Samwa buttons. They're probably better! But these buttons I got were cheap and work great. 

And I like Seimitsu controllers. Holy cow, the clicking feels so good on them (pushing up, down, back and forth on them).

Here is my purchase order to kick things off!

As you can see I bought "Female quick connectors". These make it easier to connect your wires to your buttons. You need to make sure you know how big the connectors are, and what your buttons take in the description. Normally this is pretty easy see. But just make sure you double-check all the sizes. 

I made sure to buy all the micro-controllers with the buttons. 

Arcade button with micro switch. One side goes to ground, one to the computer board.

That switch on the back is where you'll use those quick-connectors. It's easy. Same thing with the Control stick. It turns out the bottom of a control stick just uses 4 micro switches! Wire those up and connect them to your special computer board (more on that in a moment).

If you are really excited about seeing how to wire it, check out this video. I watched it to make sure I knew what I was doing. It is way more complicated than my simple layout for Bumpy Grumpy!

Bottom of the control stick with "micro switches" connected.
Wait, what side is up??? Lol, you will mess this up a lot, but it's fun to figure out.


Control Test Layout

The two red buttons are for the Brakes. The yellow ones are for the Gas. And the red control stick in the middle is for Changing Lanes. In the upper right is the Player 1 button.

Before I cut any wood panels, I wanted a way to test my button layouts and control stick. So a very easy, flexible way was to use this foam board. That way making a new hole for a button was easy. I think the whole board from the store was a few dollars, so plenty cheap. I carefully drew lines and measured out all the positions of the buttons. This let me make sure I liked the layout before committing to a piece of plywood.

Checking to see the size of things. I ended up moving the buttons outwards some more after this first layout version.


Controls to PC Connection

Since Bumpy Grumpy uses the Unity engine to port the game to PC, I needed a ways for my arcade buttons and control stick to talk to the software. How will the Gas and Brakes button send signals to my game? 

Bumpy Grumpy in action. It only needs one control stick and two buttons: Gas and Brakes.

When I play Bumpy Grumpy on PC, I can use the Z key for the Gas, and the X key for the Brakes. It turns out there are very reasonably priced pieces of hardware that can simply send keyboard commands to your computer! This special computer board is called an I-PAC and they've been around for a while. There are some pretty advanced ones, but we only need a simple one. So I grabbed the "I-PAC 2" for $40 from Paradise Arcade shop (nope, I'm not in business with them--I just like them!) 


The I-PAC 2. It's very easy to use. You simply insert your wires into the sides, connecting "1 Right" to the right direction on your control stick, and so on.

Here it is, all wired up to my test layout.

As you press the Gas arcade button the signal goes to I-PAC board, which converts to Z key and then goes to Bumpy Grumpy on your PC that the Z key was pressed and suddenly you drive forward!

The I-PAC board has a USB connection to your PC, and a little setup system for what key mappings to use. I kept the mappings as the defaults for everything, and I followed the default MAME layout in the controls. So it's easy to have Bumpy Grumpy running on a MAME system. 

Speaking of which, here is the main concept for the Guts of the cabinet.

CRT TV to PC Connection

Bumpy Grumpy runs on a fairly traditional MAME setup. That means, there is simply a Windows PC running the game. A lot of people use the MAME software to run multiple old arcade ROMs, but I am only showing off one old game, Bumpy Grumpy. But the concept is the same. Use a PC inside the arcade cabinet, connect the arcade controls to it, and display it on a TV.

But one difference is that I am using an old TV, not a HDTV. This requires a bit of "magic" to get the signal from the PC to the old TV. Fortunately it's very easy and cheap to buy this magic!

This "magic" hardware is named the "HDMI to AV" converter. It works great. It connects to the back of an old CRT TV like mine, and then has an HDMI input. You then plug a regular HDMI into this, and it connects to your PC. 

You will only need this converter if you are using an old CRT TV.

Internal Parts Review

To review, the Main Parts are:

  1. Display
    1. I chose a CRT TV for the authentic look. You don't have to fake those scanlines!
    2. The special HDMI to AV converter to go from the CRT TV to the PC.
  2. Controls
    1. Buttons and control stick, wires, connectors.
    2. I-PAC controller board to connect your buttons and stick to your PC.
  3. Keyboard and Mouse
    1. This works along side your control stick and the I-PAC controller. Basically this is nice to have plugged into your PC so you can operate Windows and look at files and such. It is needed when you are setting everything up. 
  4. PC
    1. Grab an old Dell from the year 2002 or something. They're like $60. 
  5. Power strip
    1. Plug everything into this. TV, PC, the marquee light. Then plug this into the wall for power.

That does it for the main inside parts. But I will get to some of the other fun stuff like how I did the marquee light and the coin door. 

I was VERY excited to have the game running on a CRT for the first time!

Stay tuned for the next update!

No comments: