DB25 connectors with 18 pins (2 x DB9) for a new kit

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mojo
 
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DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

I keep getting requests from people to build them retro joystick adaptors (see http://joystick.world3.net) so I'm looking at getting some PCBs made and doing kits.

I think I can squeeze everything into a DB25 jumper box, which seems to be an ideal cheap case for the project. On one end I'll have a USB connector and the other a DB25 connector which the joysticks plug in to. Adaptors for NES/SNES and various other systems will be available too. Anyway, the problem is the DB25 connectors.

Most old joysticks are have DB9s, and I have an old mouse/joystick switcher which uses a DB25 with some pins removed from the middle so it can accept two female DB9s. The pins in the middle have to be removed for the DB9s to fit. It's a brilliant idea because it perfectly fits the housing and avoids having to use two separate DB9 connectors.

I'm trying to either find somewhere I can buy DB25s with only 18 pins like that, or some way of easily making them. I see you can get blank DB25s and put pins in yourself, but apart from being a slow method those DB25s also seem to be a lot deeper than normal ones. I thought maybe I could extract the pins from a DB25, but can't see how to do it. Presumably they clip in with some kind of butterfly clip, but I have no idea how to remove them.

Any ideas? It would be an epic win if I could find a way to do it because I could then use the same PCB for multiple adaptors and the DB25 jumper boxes as enclosures, and easily support adaptors for NES/SNES/Sega Saturn/etc.

PS. Here is a picture of the switch:

Image

mtbf0
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mtbf0 »

clamp the connector. grab the end of the pin you want to extract with a pair of needle nose pliers. push.

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macegr
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by macegr »

If you're having cables made, you could specify the pin layout. Say you wanted to have a bulkhead DB25 connector wired to a 0.1" 2x10 header. They'll crimp the pins on the wires first, and then push them into the back of the empty DB25 housing.

Ask Eric at Seeedstudio for some help. He was able to get me a few hundred custom cables pretty cheaply, in under a week.

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

mtbf0 wrote:clamp the connector. grab the end of the pin you want to extract with a pair of needle nose pliers. push.
I tried that but the pins would not budge :(

I did some research and it looks like there are butterfly clips inside the housing. It might be possible to clip the ends off and squeeze them through, but it's not ideal for mass production.

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

macegr wrote:If you're having cables made, you could specify the pin layout. Say you wanted to have a bulkhead DB25 connector wired to a 0.1" 2x10 header. They'll crimp the pins on the wires first, and then push them into the back of the empty DB25 housing.

Ask Eric at Seeedstudio for some help. He was able to get me a few hundred custom cables pretty cheaply, in under a week.
I'll ask, thanks for that pointer. I am not actually using a cable, in fact the idea is to avoid using a cable at all and simply sandwich the PCB in between the solder bucket pins. So, the DB-25 will actually be more like an edge connector ;)

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westfw
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by westfw »

I think the "solder bucket" style of connector tends to be machine-made, and I'm not sure I've ever seen one with less than 25 pins. (cables OTOH get made with crimp-on pins inserted into the mount after being attached to the wires.)

Your idea is clever but also ... rather evil (it seems to me that a significant number of mating connectors wouldn't actually fit, for one thing.) I think the preferred method of handing things would be to find a box/hood vendor that could provide a casing capable of holding two "real" DB9 connectors in close proximity.

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

A suitable enclosure would be really nice, but so far I have been unable to find one. It would have to be cheap, require at most only minimal modifications, large enough to take an ATmega8 and a few other components (maybe SMT but standard through hole preferred), and most importantly have space for two DB9s and a USB connector.

I did toy with doing a version with a single DB9, but again casing was the problem. Cases like Lady Ada uses for the USBtiny ISP are available and would do, but are a bit expensive. The only other downside to using just one DB9 is that I could not support Sega Saturn or other controllers that need a large number of I/O lines. NES/SNES is okay because you just need three lines for I/O and two for sense (tie left and right together, for example).

If I could get it all in to a DB-9 hood that would be ideal, but there just isn't room. Well, maybe if I went totally SMT, but as a hobbyist soldering lots of SMT AVRs does not sound like fun. Similarly, I could also use a DB25 hood if it was all SMT, but it's easier to just use a jumper box with plenty of room.

The photo is of a mass produced device, so clearly someone managed to get hold of those connectors. I don't know what quantities they had though, but I'd be surprised if it was more than one or two thousand, if that.

adafruit
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by adafruit »

??? the pactec CNS series is like $2/each. finding something as good (and easily machinable) for less will be very hard. :/

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

They are $2 in the US, here in the UK the only place that had them wants £3.50 each (~$5) :(

adafruit
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by adafruit »

hmm that sucks. even in higher quantities?

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

Only if I order 1000 or more, but I'm only looking at doing a production run of maybe 50 and hand assembling some or doing kits. Hopefully it will be popular and I can do a larger run later...

The other advantage of using a DB25 is that I can use the same PCB for arcade joystick controllers. A lot of people like to solder their buttons and joystick to a DB25, then connect that to various things like gamepads for easy connection to one or more consoles. My adaptor goes to USB, which is tricky because there are few usable USB joypads (had to do with needing common grounds and electrically robust controller IC). Also, I have a working design for BANNED interfacing and with some fiddling it should be possible to support the XBOX 360 and BANNED too (BANNED buttons work but no d-pad, must be the HID descriptor but I don't have a BANNED to test with). XBOX 360 would be particularly nice because there are lots of classic games on XBOX Live, and you can't play SWOS without a good stick :)

In fact I was tempted to add a BANNED connection to this design, but the AVR does not have enough pins.

Anyway, here is the PCB I designed:

Image

Everything should fit nicely in a DB25-DB25 box, with a bit of hot melt glue to support the PCB at the USB end. The only issue is that the AVR will have to be soldered directly rather than socketed to account for limited height, but I have soldered several now without problems.

As for some DB9s not fitting, it is true that any with screw sockets will only fit one at a time, but all joysticks/Sega controllers use molded plastic connectors fit will fit easily. Seeedstudio are looking into the connectors. Otherwise maybe wire tags or a very small set of snips might work.

Thanks to Lady Ada too, without your site and the USBtiny kit this project would never had happened and I would never have got into AVRs.

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schill
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by schill »

You can probably remove pins from the DB25 connector using a process that I have used in the past (although never intentionally). If you can't just push them through from the front, apply a little heat to the solder-cup end with a soldering iron.

I know from experience that the plastic will melt and the pins will move. If you can heat it enough to remove the pins without damaging the plastic too much (it does like to turn brown and look kind of "melty") you should be ok.

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

Seeedstudio have managed to source them, and I'm impressed!

I also asked them about Nintendo Famicom/NES and Sega Saturn connectors. The NES ones are easily available so I'll be doing an adaptor for those, but the Saturn ones seem to be impossible to get. It's a shame because Sega Saturn controllers are simply the best ever created as far a digital gamepads go. Sega even did a rare USB version themselves.

The whole thing will be open source.

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macegr
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by macegr »

Yeah, Eric knows his stuff. Can't beat having someone stalking the huge electronics markets of Shenzen for your hard-to-find parts.

I quoted custom cables from several companies in the US, and it averaged two weeks to get a response and I wasn't happy with the price. I asked Eric for the same thing, and I had the actual cables in my hands in under a week for a tenth of the price.

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mojo
 
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Re: DB25 connectors with 18 pins (2 x DB9) for a new kit

Post by mojo »

Shenzen sounds interesting. I have checked quite a few places in Japan, including the two biggest ones Akihabara and DenDen Town in Osaka, but even there never saw anything like that. My Chinese friends in Japan keep saying I should visit China, but I only know two words of Chinese and to be honest the ability to say "hello" and "cat" probably won't get me very far :)

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