Another GP2X (or raspberry pi?) based mini (or two or three)

[ids]

Perhaps these should it be called micro's?

I've been inspired by some of the tiny builds, such as:

• Micro Donkey Kong by Bender
• Micro MS Pac Man by putto72
• Micro Star Wars by Le Chuck
• Micro Mortal Combat by 05SRT4
• Tiny MVS by Yvan256

(If you know of others, please post!)

Being curious about some of the details, I ordered not only the same joystick used by these, but some others.  Nothing is quite like having the parts in hand.

Pic:



From left to right, digikey part numbers: GH7455-ND, EG4561-ND, P12330SCT-ND, P13351SCT-ND
The third (P12330SCT-ND) is obviously meant to be driven by some kind of additional stick device, as it's just a set of tiny buttons.  This one is not likely to see use by me unless I can find a matching actuating device thing.  The rightmost is very small yet useable - I'd love to see what sort of incredibly small mame cab could be built with that - multi-williams anyone?

I do have the GP2X all set up and ready to be gutted.  That's where things stand for now.  Progress will likely be glacial.

[Yvan256]

Always nice to see another micro cabinet project!

If each panel of your cabinet can fit within a 145x95mm area, I'd be happy to help with your project, I have 2.7mm thick, white expanded PVC panels here. If you send me a Sketchup file, I could cut those on my old Roland MDX-3, as long as there's no internal radius/hole smaller than 4mm. All I would ask in exchange is one of those GH7455-ND. 

[ids]

Yvan, thanks for the offer.  I haven't even begun to think of the cabinet size/dimensions/style yet, which will likely be constrained by the decased GP2X.  I just took another quick look over at Benders DK micro - at 8.25" tall (~21cm), it will not fit your MDX-3    However, a design (such as the split UAII) could be done to accomodate.  Not knowing anything about "expanded PVC panels" - are they rigid enough for something like this?   When I'm ready for the next step, I'll ping you to see if the offer still stands.  I'll also have to get my hands on more joysticks - right now I only have what is showing in the pic (one of each).

Also, thinking out loud....  all sort of micro options come to mind, including swappable control panels  .

I can imagine a Tempest using a 6mm RGB "spinner" (Sparkfun link):


Centipede using the blackberry trackball:


Not sure if any of these can be used as inputs to a GP2x, but from what I've seen on this forum, somebody somewhere is going to do something amazing with these parts - it's just a matter of time.  Maybe even a micro frankenpanel with micro cup holders? 

[Yvan256]

Yvan, thanks for the offer.  I haven't even begun to think of the cabinet size/dimensions/style yet, which will likely be constrained by the decased GP2X.  I just took another quick look over at Benders DK micro - at 8.25" tall (~21cm), it will not fit your MDX-3    However, a design (such as the split UAII) could be done to accomodate.

Yeah, some split-panel design of that kind could make it fit inside the work area of the MDX-3.

Not knowing anything about "expanded PVC panels" - are they rigid enough for something like this?   When I'm ready for the next step, I'll ping you to see if the offer still stands.  I'll also have to get my hands on more joysticks - right now I only have what is showing in the pic (one of each).

Well, it's rigid enough but still flexible, however once the cabinet is all assembled I think it would be rigid enough. A box is always much stronger than a flat panel. As for the small cutting area of the MDX-3, if you look at my CNC64 project you can see that it's not limiting me. In fact CNC64 is almost as big as the MDX-3.

Sorry about only having white panels, but they're free leftovers from a local sign shop so I never know which colors or thicknesses I'm going to have in stock.

Not sure if any of these can be used as inputs to a GP2x, but from what I've seen on this forum, somebody somewhere is going to do something amazing with these parts - it's just a matter of time.  Maybe even a micro frankenpanel with micro cup holders? 

Frankenpanels and micro cup holders... You've been hanging with some bad crowds.

[ids]

I've been peeking in on the CNC64 from time to time - excellent work there, love the custom electronics as well.

With your kind offer in hand, I may have to accelerate my plans for this one.  I'll dig out my old copy of UAII plans from saints book and down-scale them, remove keyboard drawer bits, etc, and see how it looks.  I'm also checking the sketchup "warehouse" now for anything I can reuse ...

I wish I had the photoshop skills to take something like this and throw in a frankenpanel, cupholders, etc, it'd be lol-worthy.

[Le Chuck]

Having gone down the spinner road with the GP2X I can tell you the juice isn't worth the squeeze.  All the MAME builds for the handheld don't poll the spinner properly and there are substantial interface issues.  With analog games (Star Wars) I was able to use a caanoo easily since everything transferred over nicely there isn't a good substitution for a spinner.  That said if you get something working let me know and I'll forever be in your debt.  For now I'm focusing my micro builds on the rpi. 

[ids]

Holy crap LeChuck, that SW is effin awesome!  But i guess you already know that, since it has been covered by all news and media outlets by now.  (I don't get enough time to stay up to date with this forum),  I hope you let the poor soul down easy who offered marriage

I'll take your word regarding poor spinner support on these handhelds and give up now.

I've also been thinking of the r-pi as the guts.  I just don't know of any tiny screens that could mate with one.  I know you can drive tiny monochrome nokia screens with it.  But what about tiny colour screens from mame?  For controls that aren't simple usb, I suspect there would be ways to interface almost anything on the GPIO and maybe find a way to feed it back into Mame.  If you have any more info on any micro-mame-pi stuff, I'd be very grateful for links.  To date, the only thing I've done with a pi is embed one in my CP to drive a usb monitor, and briefly played with the Chameleon image.

thanks

[Le Chuck]

I got one of these.  I decased it and the screen is the exact size of the GP Cannoo screen.  That works out to a 19" equivalent at 1:6 scale. I'm still trying to find a nice 12v power source for the screen that can also having a 5v adapter hooked up to it for the R-PI.  I've read the Shea Silverman blog about getting MAME up and going on it but haven't gotten around to doing it yet. 

The GPIO is great and everything but for me it'll prolly be easier to just use a USB encoder from Randy so I can hook the spinner up to that and all the other controls (TRON build about 5/8 complete for the past forever).  I'll get to it eventually (and maybe even get scooped by that guy 3D printing his build) but in the mean time I've got other projects that are priority. 

Still, there are tons you can do with the GP2X or Cannoo.  I helped Bender on the code so his build direct loads into DK so we have that working on both handheld systems now.  Anything analog or digital should be good to go as long as it is two player.  The four player is less than functional on the MAME4ALL builds and I have a complete Gauntlet that isn't playable so I'm having to convert it to R-Pi also. 

[ids]

Very cool - do you have a thread for this?  That little screen does not mention resolution, but the classic games don't require much either.  Have you used it?  How does it look?  I tried a ~7" "rear view" type thing a while back and the image ranged from poor from some sources to decent from others.

For mame on pi, you could try http://chameleon.enging.com/ as a quick start.  I also had a bare mame thing going a while back as well - requires X tho.  Had that hooked up to the big tv, 55" of galaga was kinda freaky.  (no scanlines )

I assume you have the 512MB pi's - i expect performance might be better with those (or unchanged) compared with the 256MB versions.  I know the app I wrote was much better on the 512MB version.

I wonder if you could hack one of those multi-volt selectable wallwarts to do what you want?  As I understand the way some transformers work, they have multiple output lines for different voltage levels.  If built this way, you could maybe run both 12V and 5V lines from the transformer to your micro.  Not sure how a common ground would react in such a case.  Another option, although the voltage difference might be too great, would be a single 12V supply, then a 5V regulator to bring it down for the pi.  You'd probably need a heat sink in this case, if it were to work.  I'm sure you could hide a 5V regulator within a micro, even if a heat sink were required.

Also, for small builds, the maximus avr might be a better usb encoder option due to it's small footprint.

[Yvan256]

I noticed Adafruit started to sell several sizes of composite-input LCD displays.

[ids]

Thanks you for the link, Yvan.

Interesting to see a number of those small screens showing the raspberry-pi screen.

This definitely opens up some possibilities for really small "cabs".  So many ideas, so little time/money

[ids]

fwiw, I looked more into the Blackberry style trackball - it's uses four hall-effect sensors as opposed to the standard two axis optical thing.  There is arduino code readily available, so perhaps it could be modified to run on the small Maximus AVR board, or directly on an r-pi?   I'll have to try this out one day - like my todo list really needed one more entry 

[ids]

It begins...

Scaled jakobud plans printed with artwork, hardboard cut

[Le Chuck]

Nice! That's on my list for a cab to add to my micro arcade. Can't wait to see how the pearl trackball sorts out.

[CoryBee]

 

[ids]

One pic for scale, one with the printed art taped on for looks.  This is all just held together with tape for now.  The glacial pace I mentioned earlier will now begin.

When the time comes, I'll play with the blackberry trackball, look for spinner options, and mess around with the joysticks shown above.

[ids]

Spinner options, next to the micro, for scale:

1) Ripped out the guts from a dead dremmel wannabe
2) The sparkfun rotary encoder with associated knob attached

I think #1 could find itself mated with some old ball-mouse components and be made to work.  Only issue is that it doesn't spin much after you let go, but it's better than #2 which is kind of stiff.

[Le Chuck]

Why a spinner for a trackball game?

[ids]

Sorry, I'm being somewhat scatter-brained.  The spinner idea is not meant for the centipede.  I'm just thinking ahead to other potential micro's, like a tempest.  And the joysticks presented earlier would be great for....well, joystick games.  Please bear with me as I post incoherently.

[05SRT4]

Love the build so far, I had a fun time messing with my GP2X build. I'll be watching.

[ids]

Love the micro MK.  That is awesome.  I need to spend more time on this forum!

[Le Chuck]

Sorry, I'm being somewhat scatter-brained.  The spinner idea is not meant for the centipede.  I'm just thinking ahead to other potential micro's, like a tempest.  And the joysticks presented earlier would be great for....well, joystick games.  Please bear with me as I post incoherently.

Asso, I see said the blind man.

I was just going to mount the rotary encoder with a small knob on the top to the CP, it's about the right scale but some of those doodads look pretty viable.

[ids]

I was just going to mount the rotary encoder with a small knob on the top to the CP, it's about the right scale but some of those doodads look pretty viable.

Do you mean the sparkfun one?  I'm not so sure I would use it myself, as it is a bit stiff.  The LED's within are a nice feature, and it would get the job done, but the feel is wrong.  I'm currently obsessing over how to use the other one (the one with bearings).  In particular (1) how to add some kind of flywheel/weight, and (2) how to build a small tempest like knob for it.  The knob could probably be fabricated out of wood.  For the moment, however, I'm stumped on the weight - i think with some clean up and a nice weight, it would feel perfect.

[Le Chuck]

Not that one, I bought a selection from digikey and found one that I liked, smooth movement.  It was a quadrature encoder so I'll need to figure out how to get that seen on a rpi eventually, when I'm hammering on these again. 

[ids]

With respect to using a raspberry pi, I found this GPIO based keyboard code, so no keyboard encoder is required.

I also stumbled upon this: acrylic 2.4" screen micro mame cab.  He even has a tiny working OLED marquee.  Anyone gone smaller?  Adafruit has a 1.5" composite input ntsc/pal screen that's worth mame'ing    Unfortunately, however, it's only 160x240.  I might give the 2" a try: http://www.adafruit.com/products/911

[ids]

Got some replacement bearings for the spinner hack (one of them was not too good).  Pulled out the optics from an old ball mouse.  Was getting close to testing....and then...

After waiting many weeks for Adafruit to restock the items I wanted, I put through a large order.  This included a variety of their tiny NTSC screens.  Some grand plans were afoot.  However, this package was shipped by UPS, who wanted to charge all manner of b.s. fees and service charges and brokerage bullsht.  Having had countless items shipped via other carriers (USPS, FedEx, etc), I've never seen such a thing.  I will occasionally get hit with duties and/or taxes, but that's my government at work and unavoidable.  Not to be satisfied with an already exorbitant shipping charge, UPS then goes after the customer for more?  I would have just choked up the cash anyway to get my stuff, but they were asking way too much and I refused to pay, so back goes my package    Then adafruit says UPS wants another $70 to return it!  Why does anyone deal with UPS when they seem to have no regard for customer or shipper?  I feel bad about the whole thing, but c'mon UPS, stop the b.s.!

[retrostark]

search it up on youtube there is a lot, and my personal raspberry pi favorite is http://spritesmods.com/?art=rpi_arcade. i am also working on a tutorial on my little website project http://retrostarkcustomcabs.webs.com/ should be up on my site soon, i'm having tech difficulties with on of the sites i'm using to host the tutorials.

[Jigenjuke]

If you can get the Raspberry Pi to deal with bluetooth you could hack this micro keyboard apart and use the trackball on it...

http://www.jaycar.com.au/productView.asp?ID=XC4945

If you don't wanna go the bluetooth way, how about RF wireless?  This Micro Keyboard should work well. 

http://www.bhphotovideo.com/c/product/693115-REG/Solidtek_KB4251B_KB_4251B_Super_Mini_Keyboard.html

Jigenjuke

[wesbrown18]

I'd lie to mention the Beaglebone as a much better built alternative to the Raspberry Pi for $40, with a much faster CPU for MAME. There are also 3.5" to 7" LCD capes for it.  I have them on order for my own minicab project, but have worked with the Beagle Board before.

I am willing to build a FroovyArcade-like distro for it that will fit on the internal 2GB flash.

http://beagleboard.org/Products/BeagleBone

http://circuitco.com/support/index.php?title=BeagleBone_Capes

[ids]

I finally got around to hacking a minimus:

so it would translate the four hall effect sensors from a blackberry trackball:

into mouse movements.

I've configured advmame and advmenu to rotate, so the screen can work as a vertical.  Using this 3.5" 320x240 screen for now (but imagine a 90deg rotation):


The raspberry pi is set to 320x240, default overscan.  With the minimus connected, I enjoyed a few games of centipide - sort of, it was all a mess of wires and needs proper assembly, but it worked quite well otherwise.  I think I'll tweak the mouse code a bit to include the "accelerate" type of functionality, since the trackball does not spin freely.

I've also started prototyping a cp for it.  Used a forstner bit to provide clearance for the trackball, so the ball would be exposed properly:


added a few buttons and mounted temporarily to see if I'm on the right track:

I'm happy with the results so far.

I'll have to check MAWLER to see what vertical games run on a trackball, and how many buttons are needed.

I like the idea of a wireless keyboard - seems better than having to provide access to the USB ports.  Another option would be a wifi dongle, which would allow telnet/ssh access.

[Bender]

That is AWESOME!
That mini track all is the bomb!
Can't wait to see this one completed

[mcseforsale]

Wow, love the idea of the trackball.

Subscribed!

AJ

[BobA]

Great work.  Looks like and ideal solution for a micro TB.