Bacteria's N64/GBA combined portable - Nintendo 64 Advance

bacteria · Post by **bacteria** » Sat Aug 04, 2007 12:16 pm

Ok, making the buttons:

Glue some tin foil to mounting board (or better still, thin strong wood or fretboard), use a craft knife, remove the centre piece, leaving about 2 strips of about 5mm thick each.

Stick tiny pieces of sticky foam pads, about 5mm x 5mm each

Trim off the foil at one end

Cover with tin foil strips (leaving middle clear, as per pic), extending foil to other edge (for contacts). Make the middle piece (between the foam pads) have slack, otherwise it may tear.

Cover with self-adhesive paper (gives strength).

You can make the button more responsive if you need to by using thinner foam pads, moving the gaps between them further apart, or putting a strip between the gap (as I did below). The reason for the foam pads as that they are springy, so once you press them down, they rise again as they were before - ideal!

And put button on top. Indents are from testing with multimeter!

You need to experiment for optimum - light button press is what you want. Button only needs to be stuck in place.

Works like a charm!!

This might a a bit "Blue Peter" style, but if it works, no issue - you won't see this as it will be hidden under the case after all.

bacteria · Post by **bacteria** » Mon Aug 06, 2007 1:55 am

Couldn't update this last night, BenHeck site down again...

Experimented with making the button switch more. I found a good combination was using 2mm springy foam pads for the sides and 1mm one on top (instead of the self-adhesive paper) with the foil under it, with the button stuck on to the top of the 1mm foam pad (both layers are adhesive). The pic below shows the gap under the button for the contact, the gap being nearly the size of the button itself. The button is easy to press, about right. Time will tell the durability of it over heavy usage. (I used a screwdriver in pic below to raise the assembly).

You can't solder wires to tin foil of course, it evaporates; but you can seal it with electrical tape, the wire is stuck onto the foil making contact. You can then solder the wires together.

Ok, "home-made", but in the absence of finding alternatives, this works. Normal rubber contact buttons only work to one pair of connections, tact switches go to two pairs but both pairs are joined (so in effect, one true pair of connections); I needed two independent pairs of connections, this method was the only way I could find to achieve this. The process of making such buttons only takes literally a few minutes each, if that.

I am in two minds about having one combined Start button and one combined GBA menu/Slo-mo button; or having them separate. Below is a pic of them separate:

On reflection, I will probably make a combined Start button and keep the two bottom buttons as they are. It will prove annoying having to use two Start buttons instead of one!

The only way I can think of at the moment to get the D-pad working for both the N64 and the GBA is to make a home-made switch, similar to above, but a sliding switch; as it needs to switch on/off 5 contact pairs. This could be made, but is likely to wear out as the foil will lose its footing with sideways movement; so not a feasible option. The only sensible option for a dual D-pad therefore is probably to have two D-pads, the GBA one using the previous position and the N64 in the less good position. It looks ok here, and I have the space for it (just). Here, I can get by thumb between the main D-pad and the joystick to the second D-pad, would be ok. Only other option is the not have a D-pad for the N64 bit.

I have "project time" today, so will no doubt be able to provide various updates. Probably the same scenario as before, about 20% on actual project time, 80% of time spent taking photos, photo editing, uploading pics, updating forum blog, think time, etc.

First job of day will be to make 3 dual button assemblies, based on my findings above, and post an updated button-making guide! I must say, it is very easy to make such buttons, and takes away the usual headaches with trying to use more official rubber contact buttons.

I made a D-pad flat-type assembly (4 contacts, one common contact) for the GP2x about a year or so ago, the foam pad centre I used took a lot of abuse and worked for several months before I stopped using it; and this used only a small surface area of the foam pad to work (unlike my buttons); so my buttons should be able to hopefully withstand thousands button presses with any luck before I need to change them. (time will tell)!

I guess you guys see why I got my "Blue Peter" reputation on the GP2x forums now (see my avator logo)! Anyway, if it works with foam pads, card, tin foil, glue and tape; so be it!

bacteria · Post by **bacteria** » Mon Aug 06, 2007 3:43 am

Improved design for button, especially as the A and B buttons are larger. I thought I would upload these pics as improvements to previous design.

One thing I forgot to mention, make sure the underside of the button is completely flat, they are usually raised in the centre - trim this down flat with a craft knife.

The total width of the two strips of tin foil on the card is 15mm, stuck in place by glue; a small channel cut out (1mm) as before to keep the pieces from connecting to each other. 2mm foam pads stuck in place (self-adhesive) just under the width of the button.

Stick a 1mm foam pad onto foil

Cut them into 7mm strips

Trim off the excess foil from the other side with craft knife (to stop contact being made with the other piece)

Stick the foil pieces to blank card area with glue, place wire on top, seal it with a small piece of sticky paper (to keep it in place) then staple it down to ensure it doesn't wander. The sticky paper is optional, just helps when you are stapling.

Top of foam pad cover removed to reveal other sticky side. Put button in centre.

As before, you can see the gap; press the button down and contact is made.

If you want to have a light button push, make the gap between the two white pads (as per first pic) about 1mm wider than the button, cut a piece of the 1mm foam pad the same size of the button, stick this smaller piece onto the larger piece and the foil contacts in place; seal as before, remove the sticky surface from the foam pad from the top bit and put the button on.

I decided to modify to this, but didn't want to upload pics for a third time, otherwise I won't do anything else for ages! (pic a little blurry below, sorry).

Result:

There are several combinations you can try, personal taste as to what feels nice. The bottom line is you can make the button press as soft or as strong as you like. Experiment - make your own buttons switches - you might be surprised and like them!!

Oh yeah, one last bit on this, the backing is quite strong, but I will put a piece of thin wood under the button construction, stuck to the mounting board backing, to make sure it can't bend over time with furious button pressing!

bacteria · Post by **bacteria** » Mon Aug 06, 2007 5:03 am

Ok, made my three buttons. I have put them in place on the illustration with the buttons, to show they fit ok and don't interfere with anything else. I made the A and B buttons blue and green ones) with the lighter touch, the red one (start) is quite light. This feels right.

I have been testing my A and B buttons, they are very responsive and work really well. I am happy with them, and they are fit for purpose. As the buttons are stuck in place, they can't move about, and are also easy to mount in the case itself. Hole in one!

The red button (start) fits fine, the masking tape extends a bit too long, that is all, doesn't matter though.

I will also need to make button switches for the left and right shoulder buttons, I thought I might use the "clicky" ones from the GameCube controller (I have in bits from an old project which failed). I just need to modify them a bit, not difficult. I will leave this until later as I won't know if they will fit ok until I have started on the case. Would look nice though!

dudex77 · Post by **dudex77** » Mon Aug 06, 2007 6:27 am

So do your buttons actually feel like they have silicone contacts?

bacteria · Post by **bacteria** » Mon Aug 06, 2007 6:52 am

Yes. Feel the same to use; they really do. It took me a few attempts to get them right, responsive, dual contact, soft press (but not too soft!) - think I have it right now.

The process I use is similar to the normal rubber buttons, in essence. I have built in effect two layers (like a dome), press it down and the circuit is completed. Foam sticky pads are springy, get back to their original shape instantly - a bit like rubber substitutes.

BTW - thanks for the question, always welcome; I was starting to feel lonely here!!

This is a pic of the packs of foam pads I use:

dudex77 · Post by **dudex77** » Mon Aug 06, 2007 9:35 am

Thats quite cool but I guess as a result you cant have the same layout of buttons as a regular controller due to the size. I think I have some of that foam stuff lying around somewhere so I might try making a contact for the hell of it later. Yes, making a thorough guide would get lonely

Edit: 1000 posts w00t!

bacteria · Post by **bacteria** » Mon Aug 06, 2007 11:11 am

Still having problems, can't work out why, unless the issue is having two consoles connected into the PSone screen (one via RGB one via composite). The N64 part works fine, the GBA part - strange - GBA menu comes up fine, but things seem to run slower on the menus. My independent switch seemed to not be independent when connected to both devices, even though it is (I tested it with the multimeter and it was fine). I guess that might mean something shorting from the connections from the GBA>PSone>N64 somewhere. I am getting fed up with it, spent all today on this. I can't work out how to solve the problem, need more lateral thinking.

I might have fried the GBA board earlier when I gave it 7.5v instead of 3v; it all works fine, but there may be issues somewhere because of this, so I have just bought a cheap GBA from e-bay (cheap as the screen is scratched, which doesn't matter as it is coming off anyway) to play with that later in the week when it arrives.

I will try and set up my existing GBA into its own PSone screen and get that working fine, then hook it into my N64 system and see if it is ok then or not - if not, I will ditch the idea of a dual system, as the issue may be with the PSone screen acting as a short between the systems, if it is, I won't be able easily to resolve this.

Anyway, more work to do, no more time today. I hope I can do the dual system, I have put so much effort into it so far...

dudex77 - yes, have a go mate, let me know your thoughts.

Ben Cebhrem · Post by **Ben Cebhrem** » Mon Aug 06, 2007 12:45 pm

How about using diodes on the lines inputting video to the screens, so that there is no possible way they can be feeding back into the other system? That's all I can think of; either that or another switch for just the video lines, which seems like a pain.

bacteria · Post by **bacteria** » Mon Aug 06, 2007 3:11 pm

CFC Fodder wrote:How about using diodes on the lines inputting video to the screens, so that there is no possible way they can be feeding back into the other system? That's all I can think of; either that or another switch for just the video lines, which seems like a pain.

Using switches for the video lines is out of the question, several wires in question.

Diodes, not used these before - act like a one-way valve I read....could well be the answer, thanks. I have never used diodes before.

HELP PLEASE:

What diodes should I use please, and where (also which way round do you wire diodes)? I need to make signals pass through wires one way at the following points:

* The 3 wires for the RGB from the GBA to the PSone screen, the two other video wires from the GBA (ground and C-sync) to the PSone screen.

* The 5 wires from the D-pad of the GBA to the D-pad of the N64 (so I only need one).

* The negative power line (7.5v) connects all the system together as I am using one power supply for both (GBA, GBA Transverter, N64 mobo, N64 controller, car adapter, PSone screen). Having one power supply might be another source of the problem as all the systems connect to each other via the negative terminals (I could use two input lines instead of one (one per system) I suppose.

* PSone to N64 via the composite line and the ground.

In case it makes any difference to your recommendations, the mains power is 7.58v DC at 3amps. The GBA itself takes 3v, the GBA Transverter takes 7.58v line too.

I hope this provides the answer, I am so close but yet so far at the moment...

Post by **marshallh** » Mon Aug 06, 2007 10:48 pm

You don't want diodes on anything video-related, or the game pads. Since the composite signal is from 0-2v, the voltage drop on the diodes would darken the image, screw up the colorbursts, and it probably wouldn't sync. Same for RGB.

What you need to do is put a switch on the C-Sync line.

bacteria · Post by **bacteria** » Tue Aug 07, 2007 4:19 am

The N64 doesn't use the sync line, only the GBA does. The switch on the sync line won't make any difference therefore. Out of interest, why would the sync line make the difference? Any other ideas please?

bacteria · Post by **bacteria** » Tue Aug 07, 2007 10:29 am

Thinking about this logically, there aren't many variables to play with. On the positive side, with my new buttons (home made ones) I no longer had the issue whereby power is somehow migrating from the GBA batteries into the N64 (the 3v LED was on bizarely, no idea how it was getting power - the GBA sometimes took a few boots to work, which accounts for it) even though the N64 had no voltage going to it; and the N64 boots up fine every time.

Whilst the N64 works great, the issue is with the GBA part. There aren't many variables to play with:

1) The grounds are somehow not just acting as grounds but providing a short somewhere from the GBA board to the N64 board. I could have two power-in plugs and segregate the two systems that way, rather than a switch as presently.

2) The video/audio lines from the PSone mobo are getting voltage from the Transverter via the RGB, C-sync or ground wires and sending that voltage into the N64 system via the ground, audio or composite lines.

The answer will be to desolder the cables connecting the PSone screen to the N64 and the main power to the N64 from source; so all that is connected is the GBA system, then add the PSone ground>N64 ground cable (test), the PSone composite>N64 composite (test), audio cables from PSone screen>N64 (test), then the ground cables one by one (test each). It will be slow work, but all I can do. The only other cables I have left to disconnect and test are the power, ground and data cables to the controllers - it might be I need to try these too.

I will get some time to try in a couple of days time (assuming my old GBA mobo is working fine (may/may not), otherwise I have to wait for the new one to come; rip it apart and start again with it!).

Perhaps the dual system idea can't work; rest assured I will give it my best I can to make it work; I hate to fail - it will be nice to be able to exclaim "oh, **** it, that was the one cable which gave me so much grief and cost me days of toil to discover" and get it to work with a switch somewhere. Time will tell! One thing for sure, if it wasn't for the GBA part of the project, I would have had the whole thing in a case and finished by now!!

I will, as always, keep you guys updated. I might even find the solution!

codeman · Post by **codeman** » Tue Aug 07, 2007 8:33 pm

Hey, just a suggestion, but as you've already been told putting diodes on the video lines is a bad idea. Why not use analog switches? They make ICs specifically for that. A simple one would be the MAX4612. It has 4 switches in it, each is controlled by a simple on/off signal. You could have a slide switch or something on the outside that switched between powering the N64 switches and the GBA switches. But to make it work you'd have to make your own PCB and such, which I'm not sure if you want to go through the trouble. Good luck

timmeh87 · Post by **timmeh87** » Wed Aug 08, 2007 2:18 pm

yes. what he said.

Ben already made a solid-state "video switcher" device and posted an article on it. Just use his circuit with less switch positions.