lastfuture
Offline
Freiburg, Germany

I have this wild idea... and I'm throwing it out there to see if you people would think it could work.

If I remove the battery compartment of a Game Boy DMG-01 entirely I think would have enough space to fit the following in:
The guts of a small USB hub
The guts of an iMic USB sound card
The nanoloop USB MIDI adapter

USB power seems to be powerful enough to power the Game Boy as seen in this post: http://chipmusic.org/forums/topic/4315/ … y-for-dmg/

This essentially means if I wire it all up internally I would have a DMG with a USB cord that provided power for the unit itself and transported MIDI and audio, making it the perfect companion for my DAW.

Am I missing something or might this just work?

edit:
These are the guts of the iMic. I would wire the input to prepot and the output to the headphone jack of the DMG

Last edited by lastfuture (Nov 15, 2012 3:10 am)

Jansaw
Offline
Canada

Man this looks like such a sick project. Hopefully all the logic is sound! I have no clue personally...

ant1
Offline
uhajdafdfdfa

if it does not fit i think you can get smaller usb soundcards:
http://www.amazon.co.uk/Sweex-USB-Sound … 005625U1Q/

Vex
Offline
Louisiana

I say try it and document it very well step by step and then share it when youre ready. Im guessing itll work and it would be very very awesome if so. Only down side is it must always br plugged in to work. What would be more useful power wise would be an internal battery that you charge via usb..if you could find a small and strong enough battery pack to use. I do like this idea though keep us updated.

Goughy
Offline
The Wild Wintery North

Wow this is an awesome idea. I wish you luck, cause cramming all that in might be a challenge. Anyway. Can't wait for updates.

lastfuture
Offline
Freiburg, Germany

I'll get right on it as soon as my triwing arrives (any day now) Already have a DMG set aside for this. I'll document everything

BR1GHT PR1MATE
Offline
BOSTON

fuvk yes. id buy that in a heartbeat

lastfuture
Offline
Freiburg, Germany

I'll gladly take a smaller USB sound card if anyone knows about ones with good sound quality and stereo input. I've been scarred by a few very compact usb audio devices. I'm open to any suggestions here.

I'll use this USB hub, I guess this is the smallest form factor I can find considering I'll be removing the ports and soldering to the wires directly.

Last edited by lastfuture (Nov 16, 2012 9:09 pm)

lastfuture
Offline
Freiburg, Germany

I'm still waiting for my triwing and for the USB hub but while I'm waiting I can already do a few things.

First I verified that the Game Boy will indeed run on 5V. I did this with a universal power adapter that has a voltage switch. I could run the DMG on as low as 4.5V or even 3V with only minor dimming of the battery LED. It still played a nanoloop song just fine at high BPM (above 1000). So USB power seems to be legit.

Next I took my iMic apart and took a closer look

I found out that it has a separate PCB for the headphone jacks, which is good, because we can get rid of that since we will be soldering everything, and it makes things smaller. I didn't desolder anything, I just used a sturdy blade to get it off.


I also stripped the USB cord down and exposed the wires

A little size check. How much room will it take up?

Looking good so far smile plenty of room left once we remove the battery compartment

thebitman
Offline

You are an evil genius. I really hope this works.

Jansaw
Offline
Canada

!!!!!

fluxer
Offline

A couple things to consider:

1. I remember someone saying that LSDJ is more prone to slowdown with weak batteries, which probably means that lowering the voltage will produce the same effect. I'd try your voltage tests again with a CPU intensive LSDJ song.

2. If I remember correctly, the iMic had noticeable latency last time I used it. I was using one from when it first came out, over 10 years ago, so things may have improved, but I'd check this out

lastfuture
Offline
Freiburg, Germany
fluxer wrote:

1. I remember someone saying that LSDJ is more prone to slowdown with weak batteries, which probably means that lowering the voltage will produce the same effect. I'd try your voltage tests again with a CPU intensive LSDJ song.

The 3.5V was just to test out the limits. Since the internal regulator converts the 6V of the batteries or power supply to 5V anyway which is supposedly what almost all components use, including the CPU, and since 5V is what USB delivers I don't think I'll be too concerned right now, but I can try and really put it through its paces on less than 6V just to be safe. Got a .sav that will strain the DMG?

fluxer wrote:

2. If I remember correctly, the iMic had noticeable latency last time I used it. I was using one from when it first came out, over 10 years ago, so things may have improved, but I'd check this out

If it was over 10 years ago you had the iMic first generation. I've had several of these newer ones over the course of the last 7 years and I have experienced only very low latencies, barely noticeable. I have had latency problems after switching sample rates or number of channels while it was connected, but setting the correct sample rate, unplugging it and plugging it back in has always returned it to normal for me. 44kHz or 48kHz 2ch will probably be the only setting I'll have this set to anyway.

Krubbz
Offline
Fargo

What a good idea.  Keep us updated on how it goes!

lastfuture
Offline
Freiburg, Germany

I didn't want to wait for my triwing to arrive so I took a flathead and managed to get the screws out. Since I also don't have my rotary tool at the moment I removed parts of the battery compartment with a knife, pliers and my soldering iron. The parts I didn't remove are the two screw holes, the part that holds the audio jack and the part responsible for holding the battery door in place.


This doesn't need to be pretty, it'll do its job behind a closed battery door anyway. While I was in there I also cleaned the button pads and what else needed cleaning in my opinion.

Because I'll be wiring the headphone jack to the output of the USB sound card instead of prosounding it, I won't be needing most of the daughter board, so I cut off the part that that the jack wasn't soldered to so the electronics won't bite my ass later… better safe than sorry. I also cut the four wires on the main pcb, because they weren't attached to anything anymore. I also removed the speaker.

Finally I measured where the pins of the nanoloop USB MIDI adapter go when it's plugged into the link cable. the switch-up between pins 2 and 3 is correct, they're a twisted pair. what's IN on one side is OUT on the other.

Before I'll continue any further I will wait for the USB hub to arrive because it determines how I'll arrange things in the newly won space. Hope it won't be too long.

I've decided to solder the 5V and GND of the incoming USB cable (the one belonging to the hub) to the two battery terminals that are left over when the time has come. I hope I'm correct in assuming that this would work just as well as soldering them to the power connector.

Last edited by lastfuture (Nov 18, 2012 11:09 am)

Apeshit
Offline

You might find that the screws for the front PCB will start to strip now, since you've removed some vital plastic parts for supporting it. The PCB may also start to bend if that happens.