[MiniCad Project] - Mini Arcade Cabinet (21cm high) - 5" HDMI screen + RaspberryPi + arcade controls

The_Real_PhoenixThe_Real_Phoenix electronoobJoined: Posts: 108
edited May 11 in Tech Talk
Hey everyone!

I've started a couple of weeks ago building a mini arcade cabinet. The goal is to make something tiny enought to be on a desk, but with a screen big and fast enought to be used.

A bit of history:
Last year, after buying a cheap mini arcade machine and be uterly desapointed, a friend asked me if I could build him a small arcade cabinet, but with real arcade game: he insists on Final Fight, Shinobi, etc... in shrot, he wanted MAME but in a tiny build.
After showing him "small" ones with 10" screen and real controls (Sanwa and all) he says it was too big and wanted something small like the cheap one.

So here's the first draft I've made in cardboard to check with him the size:
F9gYycqm.jpg2U42iLTm.jpg

After agreed on the size I went into making it with a 3.5" TFT screen in SPI mode.
Fast forward one year later (yeah, I know, but to my defense I've build him a GameBoy Nano) I've finally make the screen working:
6LSiLlQm.jpg

Unfortunately, the refresh rate didn't satisfied him.
I went back on the bench and check what screen I could use.

I found a great 5" TFT screen, with a HDMI driver:
- https://www.adafruit.com/product/1680
- https://www.adafruit.com/product/2218

Screen is 120mm large (4.7") and so will my cabinet be.
To give the abilty to print sticker easily on a A4 sheet (21cm*29.7cm), the cabinet must be 21cm height tops.


So here the goals I fixed for the build:

Main Goals:
- Raspberry Pi 2/3 with easy access to replace/upgrade later
- Screen, small as possible but with a good refresh rate
- Controls looking as an arcade: Stick and 6 buttons (plus start/select/home)
- Power on/off switch
- 21cm height TOPS.

Secondary goals:
- HDMI output possible to hook it up to a big screen,
- Same with audio/video jack,
- Should be build as a "kit" in mind, especially the structure,
- Internal sounds,
- Accessibility to the SD slot of the Pi without dessambling everything,
- Close as possible to a real arcade shape,

Fancy-pantsy features:
- Lit Marquee
- Volume Control with jack sense (cut the internal sounds when plug on the jack)


Design was finished in a CAD software
plJyg62m.jpg

This would help me to keep track of measurements and test before printting the space inside the cab.

At first, I intended to use balsa wood sticks, make the parts as counter molds, then resin-cast them.

But eventually, I bought a cheap 3D printer which accelerate drastically the build:
grXXpp9m.jpg

This is a Anycubic Kossel Linear Plus. Structure will be printed in PLA.


Edit: tipos and better english :p
Post edited by The_Real_Phoenix on

Comments

  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    edited May 11
    ######## Electronics #########

    --- Controls ---
    For the controls, I've design my own PCB, which is exactly the width of the screen:
    BF0dRfUm.jpg
    4Sy2lPAm.jpg

    It will use the GPIOs of the Pi.

    The buttons are simple microswitches. The sticks is an ALPS RKJXL100401L which I deeply regret to use.
    It's a real 8 directions without microswitch contact. It's overkill and don't feel great. To give you an idea of what it feels, it some kind of very stiff analog control.
    I was seduced but the fact it has a real shaft, and was really small.
    I had to re-encode the 8 directions to 4 with diodes.
    Next revision will have something different for sure.


    --- Sounds ----

    in progress.
    Will have potentiomter for volume control, a 0.2Watts mono speaker and an Adafruit amplifier with a proper stereo to mono conversion.
    On/Off switch will be on the same board for practical reason.


    --- Outputs board ---

    in progress.
    Will deport HDMI, Power USB and A/V jack from the Pi. A/V jack will have a sense to cut off the internal speaker.


    --- Splitter ---
    I'm going to use a cheap HDMI splitter. It's not self-powered so I need a use a +5v from GPIO of the Pi.


    --- Connexions ---

    Most will be custom cables (USB and TRRS Jack). HDMI will use FPV/Drone connectors and flat ribbon cables.


    Edit: tipos and better english :p
    Post edited by The_Real_Phoenix on
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    edited May 11
    #### The Build ####

    Before everything: Does it work?
    s7wvXx7m.jpg?1

    Flawlessly. Screen is more than decent.

    Let's start to print.
    vchlaHWm.jpg
    HzVxU8Im.jpg

    Studs take 40mn to be printed. Sides around 3 hours. Neon holder about 1.5 hours, and the "bed" took 5 hours.
    Here's all the part:
    ggGk27Am.jpg

    I've glued them with cyanoacrylate (Super Glue Gel Control from Loctite), but quickly found welding the part by melting a PLA string directly on joint is more efficient, and after sanding, it's seamless:
    cEkGLqDm.jpg

    Here's the neon for the marquee. Two 5mm high lumonisty 3.3V leds in an acrylic rod frosted. Results are meh, even if on the picture it looks cool.
    La8uQDem.jpg


    Testing the FPV HDMI connector, works great, even with the HDMI splitter
    WDJuBHvm.jpg
    Urn6rcxm.jpg
    Post edited by The_Real_Phoenix on
  • jopamojopamo Stuck in Silly-con Valley Joined: Posts: 632
    Can't wait to see this all finished. Will you be posting a video onYouTube then?
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    jopamo wrote: »
    Can't wait to see this all finished. Will you be posting a video onYouTube then?

    Yes, of course. This is also why I can't go as fast as I wanted to: I need to film it.
  • RampageRampage Lurkin' Joined: Posts: 4,976
    Great work yet again. Looking forward to seeing the finished build.
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    Rampage wrote: »
    Great work yet again. Looking forward to seeing the finished build.

    Thanks. This week-end I should be able to finish the structure once for all, then put the Pi, the splitter, the screen with its board and the controls and all the cables for them.
    I should also be able to finish the PCB then send them to fab, and prepare the Illustrator file with the shell for getting a quote on the laser cut.
    After that I'd have of to wait all of them to come back.
    This will also give me the last prices I need to make a global cost of this mini cad.
  • x24x24 Eiffel Tower! Joined: Posts: 279
    Are you still going forward with that stick though?
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    x24 wrote: »
    Are you still going forward with that stick though?
    Yes, I'm going to stick (pun intended) with it and finish this build. Other solutions are either too big or doesn't feel right.
    I'll try to patch it somehow by cutting an octogate in the shell: at least I would be able to feel the directions.
  • jopamojopamo Stuck in Silly-con Valley Joined: Posts: 632
    x24 wrote: »
    Are you still going forward with that stick though?

    Would you be able to suggest an alternative?

  • x24x24 Eiffel Tower! Joined: Posts: 279
    jopamo wrote: »
    x24 wrote: »
    Are you still going forward with that stick though?

    Would you be able to suggest an alternative?

    Nothing on top of my head, it's been a while since I looked through a mouser catalog.

    Gating will probable help the issues a bit, at least help lessen the wear on the thing.
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    edited May 13
    Got a quote from Ponoko.
    Their "Free Making" is in fact up to 20$ and only runs for 10 days after you create your account. So much for me since making the cab's shell is 30$ USD and my account was created month ago. Well I could try to create a new account though.
    But shipping costs are even worse: 38$ to send it to Canada. (only 4$ if I was in the US)
    I'd have to find somewhere else.

    I've finished to weld all the studs and sand everything. Everything feels solid.
    Fixed the Pi, but the splitter which was supposed to be on top prevent to close the cab.

    Pi in its bed:
    Ygd8LDem.jpg
    zB5lmtgm.jpg

    Closing it:
    ZEVL5R5m.jpg
    vZS6k3dm.jpg

    Here's where the splitter was supposed to be:
    dCdUCE5m.jpg

    Too high! x(
    UMKKOHmm.jpg

    For an other command, I bought an other splitter, wich turns out to be a bit smaller:
    6Nh9VR6m.jpg
    AglHkTgm.jpg
    ENe1eNzm.jpg
    On the downside, the connector on the input is a mini HDMI. But it gave me ideas.

    Edit : tippo and better english.
    Post edited by The_Real_Phoenix on
  • The_Real_PhoenixThe_Real_Phoenix electronoob Joined: Posts: 108
    Not much visible work today. Spend a lot on preparation for the laser cut dimensions and PCBs (creating the component is a long process)

    Here's a (failed) test print to see if my measurements are correct for the screen bezel and the buttons layout.
    TmC2CIwm.jpg

    Also, the HDMI connector on the LCD driver board seems too long and will prevent to put the sound board on the top. Tomorrow I'll print the PCBs on cardboards to see what I can do.
Sign In or Register to comment.