Started my first portable (SNESp Retro Duo) - worklog

[zzattack]

Hey all, been reading these forums for a couple of weeks now and my parts are rapidly coming in so I'm about to get started. Actually, I hooked up my batteries so far, but that's really all.

Here's my list of needed parts:
(to buy/shipping/obtained):
- SNES Retro duo (white one)
- RGB Mod: 3x 470 µF caps, 3x 75Ω (E24 series)
- Polycase AG-85 case (gray but will probably paint it over more dark gray)
- 2x BatterySpace.com li-poly batteries 4250 mAh
- charger and protection circuit for them
- other power plug & chassis
- 5" lcd screen (zenith xbox)
- couple of white leds (4500mcd) with suitable resistors (gotta run em through ledcalc first)
- Total awesome ribbon cable(got it from my boss today)
- Couple of 5V switching regulators
- Probably a bunch less important ones that I left out for now

I chose for the retro duo over the snes mini because of PAL compatibility. I live in Europe so I'm totally paying my ass of on shipping and import duties (seriously, $89 shipping plus 35 euros import steals for the batteries and chargers from batteryspace.com alone). I got 4 batteries instead of 2 though. So, I really hope it'll be worth all the $$$. I also hope the retro duo runs mario rpg but I can't test that right now. It seems the retro duo has a KA2198BD chip on it for video output, and according to this datasheet, with some caps and resistors I'll get RGB output, which I hope to be able to test on my incoming LCD (bought it from khaag on here) some day next week.

I'll use another power plug (with charging switch) for charging my batteries so I can hook up a led to know when the charger is inserted, plus the one that came with the charger easily shorts and with some force you can totally plug it in the wrong way, which would probably explode the whole portable quickly.

I'll measure how the batteries are calibrated someday next week (probably checking every 5 minutes or so). This will be very boring. I should've gone with one 200mAh battery. This will take forever. Anyway, there's not much more I can do about that without equipment. When I get my table I'll hopefully be able to come up with some battery indicator using a few Zener diodes and a few leds. Would I be the first to do that? Doubt it.

My dad doesn't have much of tools and I live somewhere else cuz of study now, so whenever there's a bit of money left I get some more tools. I don't think I need any more than I have at the moment. For completion sake nevertheless:
- Dremel (400 series digital)
- Hot glue guns, big and small
- Soldering iron, desoldering iron etc
- maybe ill fill this in later but it's all too common anyway

I'll be posting pictures when I work on this too.

Next week I'll attempt to RGB mod the retro duo and put a 50/60hz switch in. If my screen arrives I hope to led mod it. One thing I think I read on these forums (iirc Life of Brian mentioned it), was something about replacing the LCD screens' 7805 with a DC/DC converter to cut down on power usage even more. Any more info on that? Also I'll be replacing the power plug for the charger.

For now all I have is a few pictures here. The clip for one battery broke off when I took the rubber off . I tried to find a place to directly mount my wire on it which wasn't quite easy. Can't really solder to this at all so I ended up putting a big blob of frozen solder on it together with the wire, and to hold it in place I firmly put over a paper clip which I hot glued in. Super ugly but works for now. I got a bit of silver glue (super expensive) from my boss today, I'll try that and keep hoping my screen arrives next week.

Sorry for the long text

[Mario]

Sounds like a great project. I can't wait to see it finished.

Just wondering, do you know how to use the macro on your camera? Macro is good for taking close-up pictures.

[Life of Brian]

One thing I think I read on these forums (iirc Life of Brian mentioned it), was something about replacing the LCD screens' 7805 with a DC/DC converter to cut down on power usage even more. Any more info on that? Also I'll be replacing the power plug for the charger.

Yes, look for a switching regulator that will output 5v if you want to squeeze more battery life out of your portable. And it's not switching the screen's 7805 regulator, it's just powering the SNES with it.

[zzattack]

Sounds like a great project. I can't wait to see it finished.
Just wondering, do you know how to use the macro on your camera? Macro is good for taking close-up pictures.

Those were taken using an iPhone camera, 1.3 megapixels I think so that's pretty poor. I don't think I can even zoom at all, so there's not much I can do about that. I'll be taking my sisters camera with me tonight though, so I can put up better pictures later.

Yes, look for a switching regulator that will output 5v if you want to squeeze more battery life out of your portable. And it's not switching the screen's 7805 regulator, it's just powering the SNES with it.

Yeah I have taken a couple of those form work and two from dimension engineering.
But what I meant, afaik the psone screen takes 7.5V input and I believe there's a 7805 on the psone screen, from which you could power your leds or even the SNES itself. I'm not entirely sure but I think I read about replacing that 7805 with a DC/DC converter like those from dimension engineering. Would be nice if that worked I guess, but I haven't seen it done yet so it's probably not possible.

By the way, I've chosen for the AG-85 because you wrote that you hardly needed any bondo and stuff for the case. It did occur to me that this will very most likely end up looking a lot like yours (well, I'm far from experiences so it'll probably be way worse), anyways I hope you'll see that as a compliment and not as some sort of ripoff

[Life of Brian]

When using the same project box it's hard for it to not look the same. Perfectly fine with me - it's a great box! Just make sure you measure everything multiple times, and then measure it some more so that everything fits.

I recall what you're referring to about the screen's regulators but I cannot remember what the final opinion was about using switching regulators. Intuitively I don't think there would be a problem, but that's an uninformed opinion.

[dragonhead]

make it some other color than black grey or white and it will look different enough for me! you dont see any brightly colored handhelds really. like green, or a nice bright blue, or maybe a nice shade of orange or something.

[zzattack]

When using the same project box it's hard for it to not look the same. Perfectly fine with me - it's a great box! Just make sure you measure everything multiple times, and then measure it some more so that everything fits.

I recall what you're referring to about the screen's regulators but I cannot remember what the final opinion was about using switching regulators. Intuitively I don't think there would be a problem, but that's an uninformed opinion.

It's very much alike internally as well. Well maybe it compares better to your ZN-40 because of the switching regulator, same batteries, protection board and charger (different plug though).

Dragonhead:
I got the gray textured version of the case and wasn't really planning of painting it, although it's a too light gray for me, was looking for something like an anthracite color. I'm not sure if this can be painted, I probably shoudl have gotten the flush version.

[Life of Brian]

"Flush" only refers to the spot where a label might be applied. The overall texture is the same for both models.

[zzattack]

Ah, that's good. The power plug I put on today is pretty nice too.

I tried desoldering the big power/snes-nes switch block and even though that went pretty well, I couldn't get the plug off. There was also solder on the upper side of the PCB which I absolutely couldn't reach. I carefully dremeled it off on the top and after a little wringling I could take out the pins quite easily. I bridged the pins like in the picture in the retro duo sticky and wired my batteries in again. The led (nes/snes indicator) doesn't work anymore, so I hope it's not supposed to. Can someone confirm this? Also it seems the wires are now connected like this
I haven't really got a way to test whether the unit still works, is there some easy check for this? I haven't got my screen yet and I took off the video ribbon cable as well. There's still some voltage over these pins though. It's too dark now to take pictures so I'll probably put some up later.

[Rekarp]

See the terminals at the top of the switch area that you havent hooked up? Those are for the LEDs

[zzattack]

Do you mean horizontay like the other two? If so that doesnt seem to work for me. Looking closely I think I've destroyed a trace, the green top layer comes off a bit near a trace going to the leds. Thanks for the tip, I'll try some more tomorrow.

[HBN]

Do you mean horizontay like the other two? If so that doesnt seem to work for me. Looking closely I think I've destroyed a trace, the green top layer comes off a bit near a trace going to the leds. Thanks for the tip, I'll try some more tomorrow.

If its just peeled, you can repair that pretty easy with some solder. Then just put a glob of hot melt glue over it to protect it.

[Sharp Sapphire]

I can confirm that the led doesn't turn on after you jump those two pins.

[zzattack]

I can confirm that the led doesn't turn on after you jump those two pins.

Thanks a lot. I couldn't get it to work after lots and lots of trying so I was starting to worry my board is fried already.


Today started of pretty good. I put some caps and resistors on a breakboard and soldered it to the video encoder chip on the retro duo within minutes even though the pins are a bit small. Here's a couple of images of that.






I ripped open an old SCART plug and tried putting some connection on it, but I quickly noticed there wasn't even power coming from the switching regulator anymore.

After some testing I found that everything was wired correctly. Voltages were right everywhere, so I assumed the batteries were still loaded. Connecting a led directly (well with resistor) to the batteries worked fine, altough they would only light up and immediately start fading if I connected them to the protection board. Even the voltage dropped quickly. My only guess is that the protection board is broken, as it doesn't supply any power once something is consuming power, just like it should if I were to undercharge the batteries. I replaced the protection board (wise of me to get 4 of them for 4 batteries) and it still didn't work. The problem actually got worse, the led used to light up about half a second but now it wasn't even 1/10th of a second. Replacing it again fixed it all though.

[Life of Brian]

I wonder what the problem is. I'm very interested in the RGB mod you discussed. If it works, then that makes Retro Duo an all around winner in my opinion - fairly similar cost to SNES mini, RGB, lower power consumption, and smaller size.